Sen. Bob Bennett (R-Utah), who has been relentless in his efforts to stop gay marriage in District, had introduced that amendment, but the full Senate rejected it Thursday morning by a vote of 59 to 36, with five members not voting.
Earlier this month, Bennett sought to attach a similar amendment to a Federal Aviation Administration Reauthorization bill, but that amendment was ruled out of order.
Republican Sens. Olympia Snowe and Susan Collins, both of Maine, joined all the Democrats in voting against Bennett’s latest amendment.
Their votes could be a sign that future efforts in the Senate to overturn the law will also be unsuccessful during the current Congress.
Delegate Eleanor Holmes Norton (D), the District’s non-voting representative in the U.S. House, has stated she will have to remain on “daily vigil” to guard against congressional intervention of D.C.’s marriage equality law.