Washington: If the Senate splits evenly between Democrats and Republicans in next Tuesday’s midterm elections, Vice-President Joe Biden could be the big winner.

As president of the Senate, the American vice-president gets to cast the tiebreaking vote regardless of which party controls the Senate. But 50-50 ties are much more likely when the Senate’s membership is evenly split.

Republicans already control the US House of Representative and need to capture just six seats to gain control of the Senate — something polls show seems increasingly likely.

With President Barack Obama’s unpopularity dragging his party down, Democrats are already bracing for even greater losses. Democratic hopes for averting a Republican majority rest in places like Alaska, Arkansas, Georgia, Kentucky, Louisiana, New Hampshire and North Carolina — conservative-leaning states tough for Democrats to defend.

But if Republicans only capture five seats it could raise Biden’s profile heading into 2016, when he has said he may run for president again.

It could even help him try to rival the rock-star status that Democrats have already bestowed upon Hillary Rodham Clinton.

On the other hand, it could also make Biden the face of messy political fights on Capitol Hill, potentially alienating some voters along the way.

“It makes Joe Biden suddenly a hugely relevant Washington figure,” said Douglas Brinkley, a presidential historian at Rice University. “It shows he’s a power player.”

Biden’s friends and associates say he’d relish the chance to play kingmaker. A creature of the Senate, Biden spent nearly four decades steeped in the chamber’s tradition and camaraderie, and a high-profile return would allow Biden to show former colleagues he’s still in the game.

An evenly divided Senate, however, is relatively rare in American politics.

The first time it happened was under President James Garfield in 1881, when a special session expected to last just 11 days stretched into 11 weeks as the Senate deadlocked, according to the Senate Historical Office.

A split Senate didn’t occur again until 1953, when Republican Majority Leader Robert Taft died and was replaced by a Democrat, leaving Vice President Richard Nixon as the would-be tiebreaker until other deaths gave Democrats the majority.

And the Senate was split 50-50 following the 2000 elections, giving Democrats majority control for 17 days beginning Jan. 3, 2001, since Al Gore was still vice president. Republicans gained control Jan. 20 when Dick Cheney was sworn in as George W. Bush’s vice president.

There have been nearly 250 tiebreaking votes cast by vice presidents in US history — but none by Biden. The most recent came in 2008, when Cheney cast the 51st vote for a budget amendment on the alternative minimum tax.

Even if the Senate deadlocks, it wouldn’t technically be a 50-50 split. That’s because there are two independents. Both caucus — or meet — with Democrats, so they’re counted as Democrats in determining which party has the majority. There’s a chance, though, that one of them could switch allegiances if the Republicans win the majority.

Further muddying the waters, two more independents could win seats this year as well. In Kansas, Greg Orman has said he’d caucus with whichever party wins the majority, while in South Dakota, former Sen. Larry Pressler has been coy about his intentions.

Still, an even balance of power might create an opening for Biden to play deal-broker behind the scenes, boosting his credibility as a pragmatist who can work with both parties. But if Biden gets called in to swing the vote on a controversial Obama-backed policy — an immigration bill, for example — Republicans would likely use that vote against him on the campaign trail.