In December 2000, Congress, in spite of the Justice Department’s strong opposition, amended the Interstate Horseracing Act of 1978  and specifically expanded the definition of “interstate off-track wager” to include pari-mutuel wagers transmitted between states by way of telephone or other electronic media, as follows:
[T]he term–. . . ‘interstate off-track wager’ means a legal wager placed or accepted in one State with respect to the outcome of a horserace taking place in another State and includes pari-mutuel wagers, where lawful in each State involved, placed or transmitted by an individual in one State via telephone or other electronic media and accepted by an off-track betting system in the same or another State, as well as the combination of any pari-mutuel wagering pools; 
The plain language of the revised statute would appear to permit interstate pari-mutuel wagering over the telephone or other modes of electronic communication, including the Internet, so long as such wagering is legal in both states. The legislative history of the amendment seems to support this conclusion.
Specifically, Congressman Frank R. Wolf (R-VA) expressed the following concern:
Mr. Speaker, . . ., this conference report contains a provision that deeply troubles me. I want Members of this body to be aware that section 629 . . . would legalize interstate pari-mutuel gambling over the Internet. Under the current interpretation of the Interstate Horse Racing Act in 1978, this type of gambling is illegal, although the Justice Department has not taken steps to enforce it. This provision would codify legality of placing wagers over the telephone or other electronic media like the Internet. 
In his statement that accompanied the signing of H. R. 4942, former President Clinton acknowledged the Justice Department’s objection to the amendment as follows:
[S]ection 629 of the Act amends the Interstate Horseracing Act of 1978 to include within the definition of the term ‘interstate off-track wager,’ parimutuel wagers on horseraces that are placed or transmitted from individuals in one State via the telephone or other electronic media and accepted by an off-track betting system in the same or another State. The Department of Justice, however, does not view this provision as codifying the legality of common pool wagering and interstate account wagering even where such wagering is legal in the various States involved for horseracing, nor does the Department view the provision as repealing or amending existing criminal statutes that may be applicable to such activity, in particular, sections 1084, 1952 and 1955 of Title 18, United States Code. .
Here is the text of the Interstate Horse Racing Act:
15 U.S.C. 3001, et seq.
Last visited Jan. 26, 2005
§ 3001. Congressional findings and policy
(a) The Congress finds that—
(1) the States should have the primary responsibility for determining what forms of gambling may legally take place within their borders;
(2) the Federal Government should prevent interference by one State with the gambling policies of another, and should act to protect identifiable national interests; and
(3) in the limited area of interstate off-track wagering on horseraces, there is a need for Federal action to ensure States will continue to cooperate with one another in the acceptance of legal interstate wagers.
(b) It is the policy of the Congress in this chapter to regulate interstate commerce with respect to wagering on horseracing, in order to further the horseracing and legal off-track betting industries in the United States.
§ 3002. Definitions
For the purposes of this chapter the term—
(1) “person ” means any individual, association, partnership, joint venture, corporation, State or political subdivision thereof, department, agency, or instrumentality of a State or political subdivision thereof, or any other organization or entity;
(2) “State ” means each State of the United States, the District of Columbia, the Commonwealth of Puerto Rico, and any territory or possession of the United States;
(3) “interstate off-track wager ” means a legal wager placed or accepted in one State with respect to the outcome of a horserace taking place in another State and includes pari-mutuel wagers, where lawful in each State involved, placed or transmitted by an individual in one State via telephone or other electronic media and accepted by an off-track betting system in the same or another State, as well as the combination of any pari-mutuel wagering pools;
(4) “on-track wager ” means a wager with respect to the outcome of a horserace which is placed at the racetrack at which such horse- race takes place;
(5) “host State ” means the State in which the horserace subject to the interstate wager takes place;
(6) “off-track State ” means the State in which an interstate off-track wager is accepted;
(7) “off-track betting system ” means any group which is in the business of accepting wagers on horseraces at locations other than the place where the horserace is run, which business is conducted by the State or licensed or otherwise permitted by State law;
(8) “off-track betting office ” means any location within an off-track State at which off-track wagers are accepted;
(9) “host racing association ” means any person who, pursuant to a license or other permission granted by the host State, conducts the horserace subject to the interstate wager;
(10) “host racing commission ” means that person designated by State statute or, in the absence of statute, by regulation, with jurisdiction to regulate the conduct of racing within the host State;
(11) “off-track racing commission ” means that person designated by State statute or, in the absence of statute, by regulation, with jurisdiction to regulate off-track betting in that State;
(12) “horsemen’s group ” means, with reference to the applicable host racing association, the group which represents the majority of owners and trainers racing there, for the races subject to the interstate off-track wager on any racing day;
(13) “parimutuel ” means any system whereby wagers with respect to the outcome of a horserace are placed with, or in, a wagering pool conducted by a person licensed or otherwise permitted to do so under State law, and in which the participants are wagering with each other and not against the operator;
(14) “currently operating tracks ” means racing associations conducting parimutuel horseracing at the same time of day (afternoon against afternoon; nighttime against nighttime) as the racing association conducting the horseracing which is the subject of the interstate off-track wager;
(15) “race meeting ” means those scheduled days during the year a racing association is granted permission by the appropriate State racing commission to conduct horseracing;
(16) “racing day ” means a full program of races at a specified racing association on a specified day;
(17) “special event ” means the specific individual horserace which is deemed by the off-track betting system to be of sufficient national significance and interest to warrant interstate off-track wagering on that event or events;
(18) “dark days ” means those days when racing of the same type does not occur in an off-track State within 60 miles of an off-track betting office during a race meeting, including, but not limited to, a dark weekday when such racing association or associations run on Sunday, and days when a racing program is scheduled but does not take place, or cannot be completed due to weather, strikes and other factors not within the control of the off-track betting system;
(19) “year ” means calendar year;
(20) “takeout ” means that portion of a wager which is deducted from or not included in the parimutuel pool, and which is distributed to persons other than those placing wagers;
(21) “regular contractual process ” means those negotiations by which the applicable horsemen’s group and host racing association reach agreements on issues regarding the conduct of horseracing by the horsemen’s group at that racing association;
(22) “terms and conditions ” includes, but is not limited to, the percentage which is paid by the off-track betting system to the host racing association, the percentage which is paid by the host racing association to the horsemen’s group, as well as any arrangements as to the exclusivity between the host racing association and the off-track betting system.
§ 3003. Acceptance of interstate off-track wager
No person may accept an interstate off-track wager except as provided in this chapter.
§ 3004. Regulation of interstate off-track wagering
(a) Consent of host racing association, host racing commission, and off-track racing commission as prerequisite to acceptance of wager
An interstate off-track wager may be accepted by an off-track betting system only if consent is obtained from—
(1) the host racing association, except that—
(A) as a condition precedent to such consent, said racing association (except a not-for-profit racing association in a State where the distribution of off-track betting revenues in that State is set forth by law) must have a written agreement with the horsemen’s group, under which said racing association may give such consent, setting forth the terms and conditions relating thereto; provided,
(B) that where the host racing association has a contract with a horsemen’s group at the time of enactment of this chapter which contains no provisions referring to interstate off-track betting, the terms and conditions of said then-existing contract shall be deemed to apply to the interstate off-track wagers and no additional written agreement need be entered into unless the parties to such then-existing contract agree otherwise. Where such provisions exist in such existing contract, such contract shall govern. Where written consents exist at the time of enactment of this chapter between an off-track betting system and the host racing association providing for interstate off-track wagers, or such written consents are executed by these parties prior to the expiration of such then-existing contract, upon the expiration of such then-existing contract the written agreement of such horsemen’s group shall thereafter be required as such condition precedent and as a part of the regular contractual process, and may not be withdrawn or varied except in the regular contractual process. Where no such written consent exists, and where such written agreement occurs at a racing association which has a regular contractual process with such horsemen’s group, said agreement by the horsemen’s group may not be withdrawn or varied except in the regular contractual process;
(2) the host racing commission;
(3) the off-track racing commission
(b) Approval of tracks as prerequisite to acceptance of wager; exceptions
(1) In addition to the requirement of subsection (a) of this section, any off-track betting office shall obtain the approval of—
(A) all currently operating tracks within 60 miles of such off-track betting office; and
(B) if there are no currently operating tracks within 60 miles then the closest currently operating track in an adjoining State.
(2) Notwithstanding the provisions of paragraph (1) of this subsection, any off-track betting office in a State with at least 250 days of on-track parimutuel horseracing a year, may accept interstate off-track wagers for a total of 60 racing days and 25 special events a year without the approval required by paragraph (1), if with respect to such 60 racing days, there is no racing of the same type at the same time of day being conducted within the off-track betting State within 60 miles of the off-track betting office accepting the wager, or such racing program cannot be completed. Excluded from such 60 days and from the consent required by subsection (b)(1) of this section may be dark days which occur during a regularly scheduled race meeting in said off-track betting State. In order to accept any interstate off-track wager under the terms of the preceding sentence the off-track betting office shall make identical offers to any racing association described in subparagraph (A) of subsection (b)(1) of this section. Nothing in this subparagraph shall be construed to reduce or eliminate the necessity of obtaining all the approvals required by subsection (a) of this section.
(c) Takeout amount
No parimutuel off-track betting system may employ a takeout for an interstate wager which is greater than the takeout for corresponding wagering pools of off-track wagers on races run within the off-track State except where such greater takeout is authorized by State law in the off-track State.
§ 3005. Liability and damages
Any person accepting any interstate off-track wager in violation of this chapter shall be civilly liable for damages to the host State, the host racing association and the horsemen’s group. Damages for each violation shall be based on the total of off-track wagers as follows:
(1) If the interstate off-track wager was of a type accepted at the host racing association, damages shall be in an amount equal to that portion of the takeout which would have been distributed to the host State, host racing association and the horsemen’s group, as if each such interstate off-track wager had been placed at the host racing association.
(2) If such interstate off-track wager was of a type not accepted at the host racing association, the amount of damages shall be determined at the rate of takeout prevailing at the off-track betting system for that type of wager and shall be distributed according to the same formulas as in paragraph (1) above.
§ 3006. Civil action
(a) Parties; remedies
The host State, the host racing association, or the horsemen’s group may commence a civil action against any person alleged to be in violation of this chapter, for injunctive relief to restrain violations and for damages in accordance with section 3005 of this title.
In any civil action under this section, the host State, the host racing association and horsemen’s group, if not a party, shall be permitted to intervene as a matter of right.
A civil action may not be commenced pursuant to this section more than 3 years after the discovery of the alleged violation upon which such civil action is based.
(d) State as defendant
Nothing in this chapter shall be construed to permit a State to be sued under this section other than in accordance with its applicable laws.
§ 3007. Jurisdiction and venue
(a) District court jurisdiction
Notwithstanding any other provision of law, the district courts of the United States shall have jurisdiction over any civil action under this chapter, without regard to the citizenship of the parties or the amount in controversy.
(b) Venue; service of process
A civil action under this chapter may be brought in any district court of the United States for a district located in the host State or the off-track State, and all process in any such civil action may be served in any judicial district of the United States.
(c) Concurrent State court jurisdiction
The jurisdiction of the district courts of the United States pursuant to this section shall be concurrent with that of any State court of competent jurisdiction located in the host State or the off-track State.
 See DC Appropriations, Pub. L. No. 106-553, § 629, 114 Stat. 2762A-108 (2000).
 15 U.S.C. § 3002(3).
 146 Cong. Rec. H 11230, 11232, 106th Cong. 2nd Sess. (2000).
 5 U.S. Code & Cong. News., 106th Cong. 2nd Sess., 2457-2458 (2000).