Senate Republicans said that while they may not have the muscle to block a new Supreme Court nomination should Justice John Paul Stevens retire this term, the fight could turn out to be a boon for the party come November 2010.

Stevens, who will turn 90 in April, has only hired one law clerk for the court’s current session, rather than the standard three or four. Because retiring justices only retain one clerk, speculation has grown that the leader of the court’s left wing may be preparing to step aside.

Senate consideration of President Barack Obama’s second high court pick would be starkly different than that of Justice Sonia Sotomayor, whose confirmation brought few fireworks and moved with relative ease. Many Senators predicted that another Supreme Court nomination would not move so smoothly and would instead more closely mirror the partisan high court brawls of the 1980s.

While conservatives were never able to mount a strong opposition to Sotomayor — in part because of her moderate record as a federal jurist — a more liberal nominee would likely incite a major GOP offensive.

Republicans noted that Supreme Court nominations are a unique event in the Senate: They force all other issues to the background as the chamber works its way through the process.

“Any Supreme Court nomination takes center stage. … There’s nothing that compares with it. [Even] if there’s a health care debate or an energy debate and a nomination comes up, then that nomination takes center stage,— Senate Republican Conference Chairman Lamar Alexander (Tenn.) said.

Even with health care reform likely to push two other big-ticket items — climate change and immigration reform — into next year, a Supreme Court confirmation fight would likely trump the agenda.

If a nomination comes next year, it would not only dominate Beltway politics, but also serve as a major topic of the 2010 midterm elections.

“If it’s 2010, that’s an election year and it’s an issue that really energizes the Republican base,— Senate Republican Policy Committee Chairman John Thune (S.D.) said.

Adding fuel to the fight is the likelihood that Obama’s next choice is expected to be more liberal than Sotomayor, reflecting Stevens’ bent on the court.

A senior Democratic aide said Democrats will almost certainly pressure Obama to replace Stevens with “a really strong liberal— candidate who is young enough to remain on the court for decades.

Republicans agreed, noting that while Obama could avoid the fight by tapping a conservative, a liberal jurist would meet significant resistance. “It depends on who the candidate is,— Thune said.

Republicans will also have had more than a year to investigate many of the likely candidates to replace Stevens. The early list includes U.S. Solicitor General Elena Kagan, Homeland Security Secretary Janet Napolitano, 7th U.S. Circuit Court of Appeals Judge Diane Wood and Cass Sunstein, confirmed last week to head the Office of Information and Regulatory Affairs.

That would mean a much quicker response from opponents than was practical for the Sotomayor confirmation. Sotomayor replaced Justice David Souter, a relatively young jurist whose retirement came as somewhat of a surprise.

Most of the names circulating are considered considerably more liberal than Sotomayor and in many cases have more name recognition with conservatives. Sunstein, for instance, has been criticized by conservatives for his role in developing the Democrats’ strategy against former President George W. Bush’s judicial nominations.

Republicans have experienced a recent resurgence in their political confidence this summer, thanks in large part to their successful messaging efforts on the health care reform fight.

Unlike last spring when Sotomayor was first nominated, the GOP believes it has some wind at its back.

Republicans have begun to demonstrate the type of discipline that defined them in the 1990s when they retook control of Congress. Republicans, including those like Sen. Chuck Grassley (Iowa) who are willing to work with Democrats, have also become increasingly impatient with the Obama administration’s approach to bipartisanship.

The GOP still would not have the numbers to actually filibuster a Supreme Court nominee as Democrats will likely have 60 in their Conference by the time another confirmation vote occurs. But a renewed sense of confidence and a more aggressive messaging campaign could mean a significantly more bruising confirmation battle than Sotomayor saw.