DES MOINES, Iowa -- Two veteran Republican strategists are abandoning John McCain's campaign in Iowa, dealing another blow to his struggling presidential bid.

And in another setback, Florida campaign co-chair and state Rep. Bob Allen was arrested Wednesday after offering to perform oral sex for $20 on an undercover male police officer.

In Iowa, Ed Failor Jr., said Thursday that he and Karen Slifka plan to notify McCain of their resignations by letter. Both are GOP operatives with deep ties in Iowa, which holds the first-in-the-nation caucuses, and national politics.

"As much as I like Senator McCain, it's not a team I'm willing to stay involved with any longer," Failor said.

Once the GOP front-runner, McCain's second presidential candidacy has been foundering on all fronts. His support has been dropping in national polls and his top GOP rivals, former New York City Mayor Rudy Giuliani and former Massachusetts Gov. Mitt Romney, have easily outdistanced him in fundraising. Over the past week, he has accepted the resignations of two top aides in his national campaign, laid off more than half his staff, narrowed his strategy to three states and disclosed he had only $2 million to spend.

Failor ran the Iowa field operation for President George W. Bush's campaign in 2004, assembling a deep campaign organization that energized social and religious conservatives. Bush narrowly won the state, the first time since 1984 that a Republican had prevailed in Iowa in the general election.

Failor also works for Iowans for Tax Relief, a conservative group that runs the state's largest political action committee.

Slifka came to the McCain campaign from her role as a strategist for the Republican National Committee.

Both had close ties to Terry Nelson, who served as McCain's campaign manager until his departure this week.

The defections are the latest sign of trouble for McCain in Iowa.

Jeff Lamberti, a former GOP legislative leader who is a co-chairman of McCain's Iowa campaign, said staff cuts in the state and the loss of major strategists is a blow.

"I'm not hearing a whole lot, to be honest," said Lamberti. "It definitely is tougher in Iowa. You need to be here, you need to have people on the ground."

Some wondered whether McCain could get backers out on caucus night, in the dead of winter, to argue politics, without experienced staffers in place. The caucuses are scheduled for Jan. 14.

"It's boots on the ground and they had that and they were going rather well, I thought, this winter and spring," said Chuck Laudner, executive director of the Republican Party of Iowa. "It just evaporated overnight on them."

In more bad news for McCain, a co-chair of his Florida campaign -- state Rep. Bob Allen -- was arrested Wednesday after offering to perform oral sex for $20 on an undercover male police officer, authorities said.

Allen, 48, was seen coming in and out of a restroom three times at a park in Titusville, Fla., said police Lt. Todd Hutchinson. He then approached an undercover officer and was arrested.

Money was never exchanged because, as soon as they left the bathroom, the lawmaker was arrested, police said.

Allen, who sponsored a failed bill that would have tightened the state's prohibition on public sex, scheduled a news conference at his lawyer's office to discuss Wednesday's arrest. A spokeswoman for Allen declined further comment.

Allen has been charged with solicitation for prostitution, which has a maximum penalty of one year in jail. Brevard County jail officials said Allen posted a $500 bond.

"Challenges are nothing new to me. Whether political challenges, physical challenges or even personal challenges -- how you stand up, face them and move forward defines your character and your strength," McCain wrote to supporters via e-mail July 10.

"I'm honored that you're standing with me and I'm determined to continue to face our challenges head-on and win. The stakes are simply too high to sit on the sidelines during this important crossroad in our nation's history," McCain said.