Despite a handful of calls from Republicans for Treasury Secretary Timothy Geithner to resign, most Senate Republicans are holding their fire, arguing that with few of Treasury’s top jobs still unfilled, it would be unwise and dangerous to leave a vacuum at the top.

Geithner is under fire for his involvement and knowledge of $165 million in executive bonuses paid by bailed out insurer American International Group. He has acknowledged the White House allowed for a loophole in the recently passed economic stimulus package that allowed the bonuses to go forward.

Several GOP lawmakers have said Geithner should step down, including Sen. Jim Bunning (Ky.) and Reps. Connie Mack IV (Fla.) and Darrell Issa (Calif.).

Others have firmly question Geithner without calling for his resignation. Sen. Johnny Isakson (R-Ga.) said in a statement Thursday: “In light of what has happened at AIG and Timothy Geithner’s role in the situation last year as head of the Federal Reserve Bank of New York, I think Mr. Geithner’s credibility has been severely damaged and is hindering the Obama administration’s ability to respond to the economic crisis. While the decision is the president’s or Mr. Geithner’s to make, I believe he can no longer serve the administration effectively.—

Should Geithner resign, “who’d be left? He’s been home alone for a while,— National Republican Senatorial Committee Chairman John Cornyn (R-Texas) said Thursday, maintaining that the blame lies with President Barack Obama, not his embattled Treasury chief.

“While the president has been jetting off to interview with Jay Leno or picking his NCAA bracket picks, there’s been very little focus on job one. So I’d be very concerned that there wouldn’t be anyone there— Cornyn said.

Sen. Mel Martinez (R-Fla.), agreed that it is unfair to use Geithner as a scapegoat at this point. “I’m not there. I mean, he’s the only guy over there,— Martinez said.

Sen. Olympia Snowe (R-Maine), who had her provision blocking the bonus payouts replaced by Banking Chairman Chris Dodd (D-Conn.) during the conference proceedings on the stimulus bill, argued that Senate Democrats must learn to stand up to Obama.

“I’ve been on the side where I’ve had to oppose the president of my party a lot,— said Snowe, a moderate who was often at odds with the George W. Bush administration. “It’s a situation that people are going to have to adapt … to resist these efforts when it’s obvious they shouldn’t be going in that direction.—

Snowe said Dodd and others must learn that “on one hand you’re dealing with a president of your party, and [on the other] you have to understand what’s right and what’s wrong.—