While Republicans in Congress support elements of President Barack Obama's $447 billion jobs bill, some are balking at the prospect of giving Obama a legislative victory that could help reverse his spiraling poll numbers.

In comments to Politico, Republicans said that they want to be able to place blame squarely on Obama for the sputtering U.S. economy, and worried that voting for his plan would implicate them should unemployment remain high.

Obama is on the ropes; why do we appear ready to hand him a win? said an anonymous senior House Republican aide. I just don't want to co-own the economy by having to tout that we passed a jobs bill that won't work or at least won't do enough.

As Obama pointed out in a speech unveiling the bill, Republicans have in the past supported some of the measures he was pushing, in particular a payroll tax cut extension that is the centerpiece of Obama's effort to spur consumer spending. Republicans have been contorting themselves to explain the reversal.

To assume that we're naturally for these things because we've been for them does not mean we will be for them if they cause debt, if they [have] tax increases and if they take money from the free-enterprise sector, which creates jobs, said Rep. Pete Sessions, R-Texas.

Still, Republican leadership has tentatively expressed its support for some of the measures in the bill, advocating a piecemeal approach that would allow lawmakers to consider various proposals separately. House Majority Leader Eric Cantor, R-Va., has pointed to small-business tax relief, certain infrastructure improvement projects and trade agreements with South Korea, Colombia and Panama.

We are not opposed to initiatives to repair and improve infrastructure, and believe there are reforms that can be implemented that would improve their effectiveness in a manner that supports economic growth, Cantor and Speaker of the House John Boehner, R-Ohio, wrote in a letter to Obama.