For the four Republicans who hope to challenge Democratic Gov. Tom Wolf's re-election bid next year, the first "playoff game" before the May 15 primary election will be the state party's endorsement.

That endorsement vote, scheduled for Feb. 10, could determine who stays in the primary race and who gets to brag that they won the endorsement while drawing upon the financial benefits of the party's backing.

Should the party be unable or unwilling to endorse, it would be the first time in 40 years.

A looming four-way contest puts the 347 state Republican Party committee members in the sticky position of choosing between two people -- York County state Sen. Scott Wagner and state House Speaker Mike Turzai, of suburban Pittsburgh-- who have played outsized roles in helping elect Republican lawmakers.

"It's a squeamish situation for some of them," said Alan Novak, the Republican Party's chairman from 1996 through 2004.

All four candidates, including lawyer Laura Ellsworth and former health care systems consultant Paul Mango, both of suburban Pittsburgh, have told party officials they will run in the primary, with or without the party's endorsement.

Wagner is widely viewed as the favorite after announcing his candidacy a year ago, far before the others. The day after Turzai announced his candidacy in November, Wagner's campaign released a list of 64 state committee members who, it said, had endorsed him.

No other candidate has released a list of state committee supporters, but the persuasion campaign is in full swing: letter writing, personal phone calls and meet-and-greets.

"It's very difficult in that all these people are getting in it, and they all think they are the most likely candidate to win it, and they all think they have enough votes at state committee to win," said Michael Meehan, Philadelphia's Republican Party chairman. "Unfortunately, all of them can't win."

No GOP-endorsed candidate has lost Pennsylvania's gubernatorial primary in 40 years.

Still, an endorsement of Wagner would represent a break with a tradition of backing establishment-style candidates.

Wagner was endorsed by Steve Bannon, President Donald Trump's former strategist who, as chairman of the right-wing Breitbart News, backed Roy Moore's failed candidacy in Alabama's U.S. Senate race that cost Republicans a seat in the chamber.

The founder of a prominent trash-hauling company in south-central Pennsylvania, Wagner touts his business credentials and is rated by the American Conservative Union as among the Senate's five most conservative senators. His penchant for speaking off-the-cuff makes him a magnet for controversy, and he has clashed openly with moderate members of his caucus.

He took office in 2014 by winning a write-in bid over the GOP's hand-picked candidate, a veteran state lawmaker, in an expensive and bruising primary in which top Republican senators spent heavily to try to defeat him. Before that, he donated heavily to conservative candidates and causes, even if it meant challenging sitting Republican public officials.

Starting Jan. 6, the state party's regional caucuses will begin meeting with the candidates and holding straw votes ahead of a formal state committee vote. Regional caucus meetings will wrap up Feb. 3, a week before committee members meet in Hershey to decide party endorsements.

"A lot of people in the counties really haven't made a decision yet," said Dick Stewart, co-chair of the Central Caucus. "I think they really want to hear the candidates make a presentation."

In election seasons since 1978, it has been obvious as to who would win the party's gubernatorial endorsement, said Blake Marles, who chairs the four-county northeast central caucus. The promise of an endorsement is typically used as a shield to avoid potentially divisive and expensive primary contests, and the GOP field is usually clear well before the party's endorsement meeting.

Not this year.

The prospect of losing the endorsement isn't scaring candidates away from running without it, and the Republican Party's cash may be stretched to help save congressional and legislative majorities in a difficult mid-term election.

"So the question is then," said Charles Gerow, a committee member from Cumberland County, "what's the endorsement's true value?"