HARRISBURG — For the first time in more than 30 years, there’s a chance that Republicans in Pennsylvania will have a hand in deciding who will be the party’s presidential nominee.

But it may not necessarily happen by pushing a button beside the name of Mitt Romney, Rick Santorum, Newt Gingrich or Ron Paul in a polling booth.

That’s because Pennsylvania is in a select group of states where party rules allow convention delegates to cast their vote on the convention floor for whomever they want, regardless of who wins the state’s presidential primary election.

That’s why Pennsylvania’s April 24 primary election is what many call a “beauty contest,” while the real battle may come down to which presidential candidate is the most successful in getting his supporters on the state’s primary ballot as convention delegates.

This year, Romney is on the path to win the required 1,144 delegates in June unless Santorum is able to prevent him from clinching the nomination before the GOP’s national convention in Tampa in late August.

If Santorum is successful, Pennsylvania’s statewide primary vote may become less important than who goes to the convention as delegates to cast votes for a Republican nominee to challenge Democratic President Barack Obama in the fall general election.

“In Pennsylvania, theoretically you can get 100 percent of the votes and end up with zero delegates,” said state Sen. Jake Corman, a Santorum supporter who is running as a delegate in the 5th Congressional District in northern Pennsylvania.

Pennsylvania has 72 delegates — the fifth most in the nation this year. Of those, 59 will be elected on April 24, 10 will be appointed by the party and three are automatically seated because they hold certain top state offices. The party’s 358-member state committee hasn’t voted to back a candidate, and Gov. Tom Corbett, a Republican, isn’t revealing who he’s supporting.

In most presidential election years, there’s a strong favorite to be the Republican standard-bearer before Pennsylvania’s primary arrives. But this year, the people who will represent Pennsylvania’s 72 delegate votes could have outsized influence if the contest comes down to a delegate fight at the convention. They could even play kingmaker.

“It would allow us to be nimble,” said Lowman Henry, a delegate candidate, state party committee member and former Dauphin County commissioner. “It’s real hard to say right now because so much of it is speculative. It would depend upon the circumstances that exist at the time of the convention.”

In the primary, 180 candidates are vying for the 59 elected delegate slots. The delegate candidates include state committee members, fundraisers and current and former congressmen.

Each presidential candidate has committed backers running for delegate slots. Some of the delegate candidates are screened by local party committees. Other candidates, like Ana Puig of the Kitchen Table Patriots in the 8th Congressional District in suburban Philadelphia, are running undecided.

“If the popular vote goes for someone who I do not personally think has a chance to beat Barack Obama, I can be persuaded to vote for someone else,” Puig said.

Corman, an old friend of Santorum’s, said he will support the candidate who wins the popular vote in his congressional district, and hopes that others will do the same in their congressional districts.