This is our weekly politics newsletter, Conventional Wisdom. In this edition, we’re covering the continuing unease with Donald Trump among some Republican delegates and leaders. (Sign up here.)

The big Republican party in Cleveland this summer looks like it could have a few fireworks after all.

It wasn’t so long ago that the possibility of a contested GOP convention had us using this space to track the allegiances of the delegates being selected to represent their states in July. If a nominee wasn’t chosen on the first ballot, the political world wondered, who would delegates support once they were released from their commitments? The hopes of those who wanted to see the first real convention floor fight in 40 years were dashed, however, when Donald Trump became the presumptive Republican nominee for president in early May. A convention fight was not to be.

But last week, there was word of a new effort to deny Trump the nomination. At least 30 anti-Trump delegates from 15 states began discussing plans to introduce a rule at the convention that would allow delegates to support any candidate they wish, The Washington Post reported on Friday. This push comes as Trump’s poll numbers have fallen and party leaders have been openly critical of recent provocative remarks that Trump has made. Both the Republican National Committee and Trump dismissed the delegates’ effort, with the RNC calling the idea “silly” and the candidate labeling it a media “hoax.” (On Saturday, Trump also accused Jeb Bush of being one of the leaders of the efforts to undermine him, so it’s not clear whether Trump really thinks it’s all a hoax.)

The last-ditch coalition faces an uphill battle. First, to change the rules, the anti-Trump delegates will need the backing of a majority of the RNC’s 112-member rules committee. Then, the new rules must be approved by a majority of the delegates at the convention. And as it stands, 1,447 of the 2,472 GOP delegates are pledged to Trump, meaning that any rule changes will require the defection of a substantial number of his delegates. Third, trying to bring other delegates into the ranks of rebellion may prove difficult: The RNC has not released the list of who will be attending the convention and has typically not released it until just days before the event begins.

There were other signs last week that the GOP’s shaky attempts to stand together behind Trump were coming undone. On Tuesday — two days after a U.S. citizen of Afghan heritage massacred dozens of people at an LGBT nightclub in Orlando — House Speaker Paul Ryan, the party’s 2012 vice-presidential nominee, repeated his objections to Trump’s proposal to ban Muslims from entering the U.S. “I do not think a Muslim ban is in our country’s interest,” he said. “I do not think it is reflective of our principles, not just as a party but as a country.” On Thursday, Ryan told The Huffington Post that his endorsement of Trump does not come with “a blank check.” And finally, in an interview that aired Sunday on “Meet the Press,” Ryan said he did not expect House Republicans to support Trump if it was contrary to “their conscience” — a statement that Dan Balz of The Washington Post described as “a green light to scatter.”

Sen. Bob Corker, a Tennessee Republican who had been mentioned as a possible running mate on a Trump ticket, said Tuesday that he was “discouraged” by Trump’s reaction to the shooting.

For now, though, Ryan and other party leaders are sticking by Trump. “Imagine the speaker of the House not supporting the duly elected nominee of our party, therefore creating a chasm in our party to split us in half, which basically helps deny us the White House and strong majorities in Congress,” Ryan said in his “Meet the Press” interview.

Yes, it’s hard to imagine, but then again, a year ago, it would have been hard to imagine that the Republican Party would be struggling to unify behind the clear winner of its presidential nomination contest a month before the convention.

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