House Republicans continued Wednesday to hammer Democrats over the issue of bringing suspected terrorists from Guantánamo Bay, Cuba, onto U.S. soil for trial — and they appear to be making headway.

After continued delays, House Democratic leaders are now punting on bringing the fiscal 2010 Commerce, Justice and science spending bill to the floor this week as Republicans gear up to use a procedural motion to force vulnerable Democrats to vote on barring the transport of detainees to New York for prosecution.

House Majority Leader Steny Hoyer (D-Md.) on Tuesday dismissed the idea that Democrats are postponing sending the bill to conference because of the prisoner transfer issue, but he conceded: “Are we concerned about motions to recommit? We are.— Hoyer speculated that as with the Homeland Security appropriations bill, Democrats would ultimately reject a motion to “impede the bringing of these very bad criminals to justice in a way consistent with the values of this country.—

But a House Democrat familiar with negotiations on the measure said party leaders have “already worked out all the issues in the substance of the bill itself— and are holding it up out of concerns that they may not have the votes to defeat the Guantánamo detainee motion.

“They’ve got to work this issue out. I think they’ve got to whip this,— the lawmaker said. “This issue of the motion to recommit, they will have to figure out how to deal with it.—

The Member speculated that Democratic leaders “probably could— defeat the motion if it were to come up now but said they are hesitant to allow the vote Thursday because about a dozen Democrats are expected to be absent. And Rep. Frank Wolf (R-Va.), ranking member on the Appropriations Subcommittee on Commerce, Justice and Science, said he still expected the bill to come up Thursday and that he would be successful on his motion to kick off the conference negotiations.

Votes on Guantánamo-related motions are nothing new to Democrats. During debate on the Homeland Security appropriations bill in October, Republicans succeeded in passing a procedural motion to bar Guantánamo detainees from being sent to U.S. prisons. The nonbinding motion, which won the support of 88 Democrats, also barred the release of controversial photos showing incidents of detainee abuse.

The conference report didn’t contain that language, however, and a subsequent GOP motion to return the bill to the conference committee to remove language allowing for detainee trials failed. But 25 Democrats still voted with Republicans to make the changes.

Of the 63 Democrats who switched their votes between those two motions, several said Wednesday they weren’t concerned about having to vote again on the thorny issue of Guantánamo.

“A motion to instruct doesn’t really do anything,— Rep. Allen Boyd (D-Fla.) said, emphasizing that those votes are nonbinding. “What’s more problematic would be a motion to recommit.—

Boyd said he wasn’t worried about more votes on the issue but guessed that “many Members are,— particularly those in swing districts. He said he switched his votes on the Homeland Security bill because a vote for the motion to recommit would have killed the bill.

Rep. Peter DeFazio (D-Ore.) questioned what “gotcha moment— Republicans are going for and said he supports bringing Gitmo detainees to trial in New York. He said he switched his votes on the Homeland Security bill over a different provision relating to a 72-hour period to review the bill.

“If we try these people, we’ll convict them. If we convict them, we’ll execute them. That’s not a gotcha. We got them,— DeFazio said. The suspected terrorists “are going to be kept in supermax security prisons, transported with extraordinary security, maybe they’ll even be brought in cages.—

Rep. Michael Arcuri (D-N.Y.), a former prosecutor, said he supports trying detainees in New York and only switched his votes on the Homeland Security bill because he didn’t support the release of detainee photographs, a provision originally in the bill but not in the final version. He criticized Republicans for using procedural motions to try to make Democrats look weak on issues of national security.

“This is not about politics. If the Republicans want to try to make it about politics, then shame on them,— Arcuri said. One vulnerable Democrat, Rep. Jason Altmire (Pa.), said he already voted against bringing Guantánamo detainees onto U.S. soil in the Homeland Security bill and is standing by that decision.

“I’m happy to take the vote again,— Altmire said. “It’s not tough for me. That’s why I don’t understand why [the GOP] is concerned about putting people on record. We’re already on record. They know this is a big issue in the public domain. I guess they want to stir the pot.—

House Republicans have been stumbling over each other to denounce the Obama administration for planning to prosecute five Guantánamo detainees — including the alleged mastermind of the 9/11 attacks — in New York. A slew of GOP ranking members signed onto a letter to President Barack Obama on Wednesday demanding answers over the planned closure of the facility and outlining concerns with bringing suspected terrorists onto U.S. soil.

Referring to the votes on the Homeland Security bill, the letter states that a “bipartisan majority in Congress has listened to the American people and voted against importing these dangerous terrorists into the U.S.— The letter accuses Obama of defying “the will of the American people— by bringing accused terrorists into the county for trial.

Intelligence ranking member Pete Hoekstra (R-Mich.) filed a discharge petition to try to force a vote on legislation that would prevent the administration from transferring detainees to the U.S. and allow state officials to decide if they want to house them in their prisons. The bill, introduced earlier this year by Minority Leader John Boehner (R-Ohio), has 169 co-sponsors.

The Senate has been navigating the hot-button issue as well: Attorney General Eric Holder went before the Judiciary Committee on Wednesday to explain the administration’s decision to prosecute the 9/11 suspects in New York.

Majority Whip Dick Durbin (D-Ill.), perhaps recognizing the incendiary nature of the subject, has been reaching out to his Democratic colleagues to allay concerns about the prisoner transfers. Durbin has been a leading voice for his home state’s appeal to house some of the 215 prisoners held at Guantánamo. Durbin used Wednesday’s Holder hearing to speak against GOP criticism of the possible transfer.

“My understanding is that those held in military facilities — and this would be a military facility for Guantánamo detainees — are denied access to any visitors, family or friends, and the only visitation is from legal counsel,— Durbin said, rebutting a claim by Rep. Mark Kirk (R-Ill.) that detainees would be permitted visitation rights.

“So the statement that’s been made about 1,000 followers streaming across the highways of Illinois is inconsistent with the law,— Durbin said after Holder assured him that was the case.

Durbin attended a series of events in Illinois last week with Gov. Pat Quinn (D) to speak in favor of the proposed plan, which could bring as many as 3,000 jobs to the economically strapped town of Thomson. Sens. Jim Webb (D-Va.) and Joe Lieberman (ID-Conn.) are among the most vocal Democratic opponents of bringing the prisoners to the U.S. Others, such as Sen. Ben Nelson (D-Neb.), have said they want to see the administration’s plan before taking a stance.

Congressional Democrats, however, seem to be warming to the idea of moving detainees into U.S. prisons. Senators voted 57-43 to table an amendment by Sen. James Inhofe (R-Okla.) on Tuesday that would have banned the use of federal funds for upgrading security measures at prisons to house detainees. The Senate adopted similar language in the war supplemental spending bill in May by a vote of 90-6.

“I think it’s pretty clear the administration has leaned on its Members, which we think is unfortunate,— Inhofe spokesman Jared Young said. “The Senate has seemingly changed course on this.—