With Washington, D.C., voting rights legislation expected to return to the House floor as soon as this week, thousands of supporters are set to march down Pennsylvania Avenue today in the cause’s biggest advocacy event in a generation.

And while there are signs the District of Columbia House Voting Rights Act could face a tough road ahead, advocates remain optimistic that the march will rally enough support to give the effort a big boost.

“The march isn’t necessarily about the bill,” said Ilir Zherka, executive director of DC Vote, the group organizing the effort. “We aren’t going to be carrying signs saying, ‘Pass H.R. 1433.’”

But the legislation could use some help. Although supporters have been planning the march for months, its timing couldn’t be more appropriate, as its proponents hope to overcome the latest roadblock in the coming days.

The bill, which would give D.C. a full-voting seat in the House while also granting Utah an at-large seat, easily passed the Oversight and Government Reform and Judiciary committees earlier this year. But when it went to the House floor for a vote in March, Republicans, led by Judiciary ranking member Lamar Smith (R-Texas), introduced a motion to recommit that effectively tied the bill to the D.C. gun ban.

Fearing defeat, Democrats then pulled it from the floor, and Majority Leader Steny Hoyer (D-Md.) told reporters the bill should return for a vote this week, with procedural matters handled so history won’t repeat itself.

But as of Friday afternoon, the bill had yet to be added to this week’s floor schedule, although Hoyer is hopeful it could come up next week, according to a spokeswoman.

Advocates plan to use the march as one way to push the bill forward, not only in the House but in the Senate, where support for the measure clearly is weaker.

Utah Sen. Orrin Hatch (R), who is viewed as a key component of getting the measure passed, has appeared skeptical.

“I am supportive of the efforts to gain another seat for Utah. But it’s not clear that we would have the votes in the Senate to pass the bill that’s currently being debated in the House,” he said in a statement.

“Some in the Senate have expressed constitutional concerns with other provisions in the DC Voting Rights bill,” he added. “And last year, the President said he hadn’t really looked at the bill. This year, he’s indicated that he would veto it. That makes it very difficult to move this bill forward.”

Zherka admitted there are challenges ahead to get the 60 Senate votes needed to overcome a veto.

“Our strategy is to get the 60. We aren’t there yet,” he said.

Still, there is reason to be optimistic.

Part of the voting rights activities today will include a reception, co-hosted by Del. Eleanor Holmes Norton (D-D.C.) and Sen. Joe Lieberman (ID-Conn.), that is designed to “push the Senate” on the issue.

It will mark the end of a busy day for voting rights advocates, who will begin their march — held on D.C. Emancipation Day — at Freedom Plaza.

The bill’s co-sponsors — Rep. Tom Davis (R-Va.) and Norton — are expected to be joined by Rep. John Lewis (D-Ga.), former Rep. Jack Kemp (R-N.Y.), D.C. Mayor Adrian Fenty (D) and most members of the City Council for the march, which will take participants down Pennsylvania Avenue Northwest to the Capitol. A local church choir will greet their arrival on Capitol Hill just before a variety of leaders take the podium.

An eclectic mix is expected to participate, from a variety of D.C. groups to civil rights organizations to labor unions.

Even business is getting involved.

The Greater Washington Board of Trade, an area group that assists local businesses, recently pledged its support for the measure and sent Bush a letter urging him to sign the bill if it passes. And the D.C. Chamber of Commerce told its employees they could miss work to march, Zherka said.

“We’ve got just an incredible number of groups, organizations, businesses, taxi drivers, bike messengers and others coming together to support the march, in ways we haven’t seen in a long time,” Zherka said.

One goal of the march is to raise awareness of the D.C. voting rights movement outside the Beltway, Zherka added.

“When Americans know about what’s happening here, I think they are supportive of what we do,” he said.

But advocates said perhaps the most touching aspect of today’s march might be the many school groups expected to come down.

“Teachers are bringing their classes out, college students are coming out,” said Kevin Kiger, DC Vote’s communications director, who helped plan the march. “I think the residents are pumped up. It’s certainly the largest planned event in a generation for this movement.”

Marnette Federis contributed to this report.