House Republicans’ bid to force a vote on a border and immigration enforcement bill has already reached 181 signatures, including nine Democrats, amping up the pressure on Democratic leaders — and presumed GOP presidential nominee Sen. John McCain (Ariz.) — on the politically explosive issue.

GOP leaders launched the discharge petition shortly before the spring recess after weeks of considering the move. They say bottling up the bill in committee highlights another attempt by Democratic leaders to thwart the will of a majority of the House on a major issue of the day.

With nearly 50 Democrats supporting the bill sponsored by Reps. Heath Shuler (D-N.C.) and Brian Bilbray (R-Calif.), Republicans note that if those Democratic co-sponsors stood up to their leadership, they could reach the 218 signatures needed on the discharge petition to force a vote.

But signing a discharge petition is a personal affront to leadership, and securing enough Democratic signatures is a long shot, with several co-sponsors telling Roll Call that they would not do so.

“If the co-sponsors will sign, it will go to the floor,” said Bilbray, chairman of the House Immigration Reform Caucus, who said the legislation meshes perfectly with McCain’s enforcement-first campaign rhetoric. “This is exactly what Mr. McCain is talking about: Secure the borders and the neighborhoods first before you talk about the 20 million people who are here illegally.”

But Bilbray, who signed a discharge petition on campaign finance reform when Republicans were in the majority, contends that the effort will put pressure on Democratic leaders to deal with an issue that they would rather keep under wraps and put heat on vulnerable Democrats to choose between their leadership and their convictions.

“Obviously, there is a lot of arm-twisting going on,” he said. “The Democratic leadership wants to put this off until after the election so people won’t see where they stand on this issue.”

House Democratic leaders have struggled to come up with the votes for compromise legislation backed by Hispanics that would merge elements of the Shuler bill with multi-year visas for illegal immigrants and an expansion and extension of temporary-worker visas.

Bilbray said he discussed the legislation with McCain. “I pointed out this is exactly what he is talking about,” Bilbray said.

Bilbray predicted that because of McCain’s past support of broader immigration legislation, he could embrace enforcement-only measures like the Shuler bill. “McCain has the moral high ground to be firm but fair. He doesn’t have to wimp out to show he’s sensitive,” Bilbray said.

But Hispanic Members and immigration advocates argue that McCain’s reserve of goodwill in the Hispanic community will erode rapidly if he ties himself only to enforcement measures.

“McCain’s going to have to make a decision,” said Rep. Luis Gutierrez (D-Ill.), who worked for years with McCain on comprehensive immigration legislation before Senate filibusters quashed the effort last year. “What they are going to say is: Where are you today? You’ve got a great tradition and a great record, are you walking away from the table? I believe I know what he really stands for on immigration. The question is: Which McCain is going to show up? … I hope we see the one I worked with … both for him and for the country. I think that’s who he really is.”

Rep. Artur Davis (D-Ala.), an early and enthusiastic supporter of the Shuler bill, says Democrats should punt on the issue until next year when he hopes a Democratic president could tackle it and unite his party.

“It’s going to take presidential leadership,” Davis said. “It would be very hard to bring a bill to the floor that wouldn’t pose a serious risk of being hijacked,” he said. “It would be a mess.” Davis added that even if the House were to act, “the Senate isn’t going to do anything with it. … We can be patient enough to wait for it.”

Pro-immigrant groups are warning that McCain could be put in a sticky situation with the discharge petition and other GOP efforts because he has been at odds with most Congressional Republicans. He has supported President Bush’s more comprehensive approach that would provide a pathway to citizenship for illegal immigrants.

“The chance that he would reasonably have with Latino voters is being substantially undercut by members of his own party,” said Cecilia Muñoz of the National Council of La Raza.

Muñoz said Hispanic voters see the Shuler bill as “Sensenbrenner Lite,” a reference to harsher earlier legislation that prompted massive nationwide protests.

“It’s a vehicle that really focuses on a strategy that’s about rounding people up and deporting them,” she said. “The message to Latino voters is that they intend to play politics with us.”

Muñoz said McCain is walking a tightrope between Members on the right and Hispanics who respect and admire the Senator.

“Any moves that he makes to sort of appease the hard-liners on the right are going to be noticed,” she said.

Bilbray dismissed critics who argue that McCain will pay a price.

“The people that are saying this are the amnesty-first people, amnesty at all costs. You’ve got to first take care of the problem in front of you,” he said.