Thousands of Republicans from across Illinois are gathering in downstate Peoria for their state convention, where they’ll decide on the party’s platform and delegates for the national convention. 

It’s been an unpredictable election year for the GOP, and Illinois Republican party is no exception. New York businessman Donald Trump handily won the Illinois presidential primary, winning every collar county and Cook County, yet several influential state Republicans are not supporting him outright. Some, like Illinois Gov. Bruce Rauner, say they’ll support the GOP’s nominee, but they won’t mention Trump by name. 

With that backdrop, party leaders this weekend are finalizing who will represent the state as a delegate at the Republican National Convention in Cleveland this summer. 

Also on the agenda is the party’s platform and the Illinois Republicans’ official position on same-sex marriage, a topic that by Friday evening had already proved contentious among party leaders.

On Saturday, the delegation could vote on a measure that would alter the party stance. The party currently supports a definition of the “traditional family” as a marriage between “one man and one woman.” On Friday, a committee recommended new language recognizing other marriages.

State Rep. Peter Breen (R-Lombard) took issue with that vote.

“Today’s action by a narrow majority of the platform committee to redefine marriage followed a flawed, closed-door process that excluded and marginalized the deeply held beliefs of a majority of Illinois Republicans,” he said. “Republican Convention delegates deserve a full debate and a fair vote on their platform, including the definition of marriage. The credibility of the Illinois Republican Party is at stake.”

Former Illinois Republican Party chair Pat Brady called committee recommendation a “big step forward” for the party, regardless of the final decision by party leaders on Saturday.

For his part, Gov. Rauner, who has called himself the leader of the Illinois Republican Party, told reporters Friday that he would not be weighing in on any party platforms.

“I’m not gonna weigh in on particular platform issues. I’m going to leave that,” he said when asked about his position on same-sex marriage. “That’s what the delegates role is to do and I don’t want to jump ahead of that or preempt on that. I think they should do their jobs and let the will of the delegates, the will of the voters decide these issues.”

Rauner is expected to speak at the convention Saturday, as is Illinois’ Republican U.S. Sen. Mark Kirk, though both of them have said they will be skipping the RNC in Cleveland.

Lauren Chooljian covers city politics for WBEZ. Follow her @laurenchooljian. Tony Arnold covers Illinois politics for WBEZ. Follow him at @tonyjarnold.