GOP leadership aides in both chambers said Friday that while they’re not entirely clear why Democrats — who have scheduled a House floor debate on the reauthorization of the Foreign Intelligence Surveillance Act for this week — have decided to pivot to a national security fight in the middle of the public relations war over the States Children’s Health Insurance Program, they are more than happy to do so.

With the short-term extension of FISA, which was passed in August, set to expire in February, Democrats are moving forward with a legislative package that includes constraints on surveillance, which certainly will prompt a veto from President Bush.

But unlike Bush’s veto of the SCHIP bill — which was supported by a number of Republicans in the House and Senate and subsequently has caused significant heartburn for in-cycle GOP incumbents — Republicans are much more comfortable backing Bush on national security.

“On this kind of veto we have a chance to win because it’s national security,” a Senate GOP leadership aide said, adding that Senate Republican Conference Chairman Jon Kyl (Ariz.) is taking the lead on the issue in that chamber.

A House GOP leadership aide agreed, arguing that Republicans have much better “branding” on national security issues.

But House and Senate Democratic aides downplayed the move to FISA, noting it will take only two days of floor time in the House, and the Senate will not be taking it up at all. Democrats argue that SCHIP — which tests much better for the majority party — likely will dominate both chambers for much of the week.

Specifically, Republicans are planning to use the kidnapping and subsequent murder of three U.S. soldiers in Iraq earlier this year to put a “human face” on the issue, the House staffer explained. According to this aide, while Democrats’ arguments about privacy may resonate with some voters, Republicans believe using real-world examples of how a weak FISA has put U.S. troops in danger will help galvanize public support for their position.

“We’re content to have the Democrats make these abstract and obtuse privacy arguments,” the aide said. “As long as we make this debate ... about real world, human examples,” Republicans believe they can maintain party discipline on Bush’s veto and effectively fight Democrats in the public arena.

A Senate Democratic aide derided any attempt by Republicans to use the deaths of soldiers in their efforts to block the FISA bill, arguing that “by that logic if Republicans had spent the last five years conducting oversight instead of blindly following this president, there’d be a lot less soldiers killed as well.”

Additionally, Republicans also will capitalize on the Democrats’ decision to agree to a temporary FISA bill granting the Bush administration much of the latitude they now oppose against them. “What has changed fundamentally between August and today?” the House aide argued, adding that “the same reasons they had to cave then are applicable today.” Indeed, Kyl’s Conference on Friday issued a release noting that dynamic and highlighting editorials backing their position.

But it remains unclear how effective — or long lasting — the FISA fight will be for the GOP.

Democrats in both chambers have their eyes squarely set on Thursday’s House veto over-ride vote on SCHIP, and while at this point it appears likely it will fail, aides in both chambers said that issue remains the focus of their messaging work for much of the week. And following the vote, Republicans can expect a new round of attacks from Democrats and their outside allies on the issue.

Additionally, Senate Republicans are facing an added, and certainly unwanted, distraction — NBC’s planned prime time interview with Sen. Larry Craig (R-Idaho) on Tuesday evening and during the “Today” show’s Wednesday morning broadcast.

Although GOP aides declined to comment on the interview, it assuredly will be a topic of discussion on Capitol Hill and could cause fits for Senate Minority Leader Mitch McConnell (R-Ky.). Although McConnell initially called for an ethics investigation into Craig’s arrest and subsequent guilty plea in August as part of a public sex sting, Craig’s decision to remain in the Senate earlier this month prompted McConnell to cancel a major press event that aides had hoped would be the launch of Republicans’ SCHIP counteroffensive in the chamber.