Senate Majority Leader Harry Reid (D-Nev.) appears to be having trouble figuring out when, how or even whether he can bring comprehensive immigration reform to the Senate floor this year.

The Majority Leader, who faces a tight re-election race in Nevada, has been adamant when speaking to Latino audiences that he will pass something on the issue. Speaking at a rally of more than 6,000 largely immigration reform activists, Reid on Saturday vowed to take up the issue upon returning to the Senate from the spring recess. “We’re going to come back, we’re going to have comprehensive immigration reform now,” Reid told the crowd.

But on Tuesday, Reid backed off that pledge amid a packed Senate schedule of jobs bills, appropriations measures and the confirmation process for a Supreme Court nominee. Reid acknowledged to reporters, “We won’t get to immigration reform this work period.”

Just hours later, Reid’s office sent out a press release targeted at Spanish language media that appeared to have Reid once again changing directions. In the release, Reid spokesman José Dante Parra reaffirmed Reid’s commitment to passing immigration reform legislation this year as well as his Saturday statement that he would take it up soon.

“On Saturday in Nevada, he reaffirmed his unyielding support for such a bill. His commitment remains as firm today as it was Saturday, as it was in January of last year, and as it has been over the years he has taken on the challenge of fixing our broken system,” Parra said.

Reid’s Saturday speech was not the first time that he appeared to promise swift passage of immigration reform; during the 2009 confirmation process for Justice Sonia Sotomayor, Reid indicated immigration was a top priority that he hoped to finish before year’s end.

Reid’s commitment to the issue is well-documented, but the biggest hurdle to even taking up a bill may be a lack of interest among his colleagues.

Privately, Democratic aides acknowledge that Reid would run into resistance from moderate Democrats such as Sens. Blanche Lincoln (Ark.) and Ben Nelson (Neb.), who were forced into taking politically damaging votes on health care over the past six months and have no appetite for another major policy fight.

Nelson on Wednesday rejected the idea of taking up immigration reform until border security issues are addressed. “I don’t think we should do anything on immigration until and unless we have the border security issue” resolved, Nelson said, adding that border security legislation must be in place before he would consider supporting immigration reforms.

“Get the border secured [first]. … Any country that can’t control its borders is going to have a very tough time ensuring its national security or economic security,” he said.

Republicans agreed — after all, they used similar arguments in rejecting comprehensive reform in 2008.

National Republican Senatorial Committee Chairman John Cornyn (Texas) said increasing drug violence along the Mexican border has cooled interest in immigration reform, and he argued that border security must be ensured before broader reforms are considered.

“The violence in Mexico … has created more uncertainty,” Cornyn said. “I’ve always felt that border security is a precondition to the public accepting a broader approach” to immigration.

Senate Republican Conference Chairman Lamar Alexander (Tenn.) said: “Most of us think now is not a good time with all the trouble on the border. It’s not the right atmosphere for dealing with comprehensive immigration reform.” He added that Republicans were “likely to come forward with a number of proposals on securing the border” in the next few months.

Even a bipartisan effort by Sens. Charles Schumer (D-N.Y.) and Lindsey Graham (R-S.C.) has stalled in recent months. Graham insists that he will not sign off on a bill unless additional GOP co-sponsors can be secured. But despite lobbying from Graham and Schumer, no other Republicans have stepped up to back a comprehensive bill.

“I think that a lot of my colleagues have concern about the violence on the border that we’ve seen in recent weeks. … I think that there’s a lot of concern that we haven’t sealed the border yet,” Sen. George LeMieux (R-Fla.) said.

Republicans argued that Reid — a master vote-counter — is well aware of the political dynamics surrounding immigration and charged that he is pandering to Latino voters as part of his re-election efforts. “I think it’s posturing,” Cornyn said.

“I think they’re trying to appeal to a particular constituency,” Minority Whip Jon Kyl (R-Ariz.) said. “But if I was that constituency, I would call their bluff.”

Democrats rejected any criticism of Reid, saying his position on immigration reform has not changed.

Reid spokeswoman Regan Lachapelle maintained Wednesday that the Majority Leader has been consistent since the beginning of 2009 about his commitment to passing immigration legislation, noting that he has repeatedly said it is one of his top priorities that he hopes to pass “soon.”

“He has been very, very consistent on immigration,” Lachapelle said. “Nothing has changed here.”

Reid will likely have another chance to voice support for immigration reform on May 19 — the date that Mexican President Felipe Calderón is scheduled to address a joint session of Congress.

Emily Pierce contributed to this report.