Supporters of the District of Columbia House Voting Rights Act said Tuesday they have the votes needed to defeat a filibuster — but with the Senate facing a packed schedule, it is unclear if the measure will reach the floor before the August recess.

When Majority Leader Harry Reid (D-Nev.) outlined the schedule for the reminder of 2007 on the Senate floor Tuesday morning, he said the chamber would focus on national intelligence, Homeland Security appropriations and children’s health care before breaking for the summer.

And a Reid spokesman told Roll Call that the ambitious schedule set for the next couple of weeks and recent Republican efforts to derail legislation have created obstacles for scheduling the D.C. measure. Still, the possibility Reid will bring the bill to the floor before the recess remains.

“This is a priority for him, he’d like to get this to the floor as soon as possible,” spokesman Jim Manley added.

But when the Senate takes up the legislation, it likely will run into another obstacle: Minority Leader Mitch McConnell (R-Ky.), who has threatened a filibuster.

“He has said publicly and privately that this legislation as written is unconstitutional, and if we are to do this legislation it should be done in a constitutional way,” McConnell spokesman Don Stewart said Tuesday.

He added that a filibuster remains possible, as “nearly any controversial matter before the Senate generally requires 60 votes.”

It is only within the past day or so that voting rights supporters got the signals that they had the 60 votes to overcome such a filibuster, said Wade Henderson, president of the Leadership Conference on Civil Rights. But supporters declined to name which Republican Senators recently have pledged support for the bill.

When they will have an opportunity to show their support remains in question.

During a conference call Tuesday, supporters remained confident that despite the timing challenges facing the measure, it will reach the floor soon.

“Harry Reid has promised to bring the bill up,” said Sen. Orrin Hatch (R-Utah), who sponsored the measure alongside Sens. Joe Lieberman (ID-Conn.) and Bob Bennett (R-Utah). “I think he has an obligation to do this.”

But Hatch also admitted scheduling is an issue.

“If things go the way they have gone the first seven months of the year, we might not be able to get to it,” he said.

Henderson said advocates are in contact with Reid’s office and believe there is still time to modify the calendar.

Henderson admitted that delaying a floor vote until after the recess poses an obstacle because supporters will have to work to ensure they do not lose votes.

But it won’t kill the effort, he said.

“Obviously, we’ve had setbacks in the past, but we’ve overcome them,” Henderson said.

The voting rights legislation would grant Democratic-leaning D.C. a full voting seat in the House while also giving an additional Representative to Utah, the largely Republican state that just missed getting a fourth seat after the 2000 Census.

Its compromise framework was the brainchild of Rep. Tom Davis (R-Va.), who sponsored the measure in the House alongside D.C. Del. Eleanor Holmes Norton (D). That bill passed that chamber in a 241-177 vote in April.

In June, the Lieberman-chaired Homeland Security and Governmental Affairs Committee passed a companion measure in a bipartisan 9-1 vote. Since that time, supporters have lobbied an array of Senate offices to get the 60 votes needed to overcome a filibuster.

Several Republicans already have joined Hatch and Bennett in publicly aligning with the bill. When the bill came up in committee last month, Governmental Affairs ranking member Susan Collins (R-Maine) and Republican Sens. Norm Coleman (Minn.) and George Voinovich (Ohio) voted for the measure.

Despite their confidence, voting rights supporters said they hope to avoid a filibuster.

As part of that effort, advocacy group DC Vote urged supporters to call their Senate offices on Tuesday in support of the bill.

Residents of D.C. — who do not have their own Senators — phoned McConnell’s office asking that he not filibuster the measure, said Ilir Zherka, executive director of the group. Today, dozens of supporters are expected to rally outside Senate buildings and visit Member offices in support of the bill.

“We may be able to get some people to vote for cloture who might not be able to vote for the bill itself,” Henderson said.

Even if the measure does get through Congress, it faces a major threat from the White House. Advisers to President Bush repeatedly have said they would recommend he veto the bill should it reach his desk.

But both Hatch and former Rep. Jack Kemp (R-N.Y.), who has lobbied for the measure, said Bush is not likely to use a veto. The president probably has not even looked at the bill extensively, Kemp said.

Henderson pointed out that when the Senate committee passed the bill, a Collins-backed amendment was included that would expedite any court challenge to the measure. Thus, if the president and others are worried about constitutionality, they should trust the courts to handle those issues, he said.

“I think there are decent arguments on both sides, but I think the prevailing argument should be that these people have a right to vote,” Hatch said.