Today is the second chance in as many years for the District of Columbia House Voting Rights Act, with the Senate set to vote on a procedural motion that could lead to the bill’s passage by the end of the week.

If the cloture vote fails, it will be a significant — and perhaps fatal — blow to the bill’s chances this year. With Democrats eager to churn out legislation on the economy and health care, the District’s plight is likely to be pushed into the background, as it was when a nearly identical bill failed to pass the same motion in 2007.

But supporters and opponents alike expect the cloture vote to get the 60 nods it needs, thanks to a Senate with 58 Democrats and a few supportive Republicans such as Utah Sen. Orrin Hatch and Maine Sen. Susan Collins.

Where the bill will go from there, however, is unclear.

Not only do constitutionality questions linger, but the House and Senate versions of the bill differ in one important way: how to give Utah its extra seat.

The seat makes up for the one Utah narrowly missed in the 2000 Census. As a political compromise meant to gain the support of Republicans, the provision often takes a back seat. But it could delay Congressional passage if the House and Senate can’t come to an agreement.

Since 2007, Congress has flip-flopped between giving Utah an at-large seat and handing the state a new district.

An at-large seat is politically friendly but constitutionally questionable, while a new district means the Utah Legislature will have to redistrict the state now, only to alter that plan after the 2010 Census figures are calculated.

“The at-large district, in my view, is unconstitutional under the ‘one man one vote’ line of cases. People in Utah would in effect be represented by two Representatives,” said Jonathan Turley, a George Washington University law professor who has challenged the bill’s constitutionality at several Congressional hearings. “The Supreme Court has always been very skeptical of an at-large district because of how they dilute or magnify the votes of citizens.”

But the House seems on track to pass a version with the at-large seat.

In 2007, D.C. Del. Eleanor Holmes Norton (D) and then-Rep. Tom Davis (R-Va.) ditched the 4th district option because they were afraid it wouldn’t garner enough support in the House, where several Democrats raised concerns about redistricting so soon after the 2006 elections.

Now, with the 2010 Census quickly approaching, the newly created district would last for only a few years before being redrawn.

The House Judiciary Committee is expected to mark up the House bill soon, but Chairman John Conyers’ (D-Mich.) office didn’t respond by press time to inquiries on whether the committee might change the bill to require a new district rather than an at-large seat.

Ilir Zherka, executive director of voting rights group DC Vote, said he is confident the bill will be deemed constitutional whether the seat is at-large or a new district.

“We don’t have a position on which of those two options are better,” he said. “But I think it’s going to be critical that the conference between the House and Senate resolve that issue as quickly as possible.”

If that issue is resolved, the voting rights bill will still have to pass constitutional muster for its main purpose: providing a full House seat to Washington, D.C. Right now, it has a Delegate who can vote in committees but not on the floor.

Voting rights advocates claim the Constitution’s District Clause trumps the Composition Clause, which stipulates that Representatives are chosen by the “people of the states.”

Opponents to the bill, Turley included, argue that the voting rights act changes the House — rather than just affecting the District — and thus the Composition Clause applies.