For Donald Trump, his campaign’s historically ugly fundraising disclosure couldn’t have come at a worse time. Republican leaders now have all the cover they need to pursue what was once unthinkable. Though still talked about in whispers and behind closed doors, a convention putsch is no longer an impossibility. Moreover, some GOP leaders are not only fanning the flames of dissent; they are positioning themselves at the head of it. Case in point: Wisconsin Governor Scott Walker.

For weeks, an implausible campaign to approve a rule that would release Cleveland convention delegates from the obligation to cast their ballots for Donald Trump had been gaining steam. What was previously a quixotic effort began to accumulate momentum when public polling revealed that Trump had badly damaged his image and splintered the GOP following his attacks on Judge Gonzalo Curiel’s ethnicity. Soon after that, a Reuters/Ipsos poll that showed an 11-point advantage for Democrats on the generic congressional ballot question, raising the prospect that the GOP might not only lose control of the Senate but the House, too.

Then came Trump’s latest financial disclosure. It confirmed that the spending disparity between Hillary Clinton and Donald Trump in November would almost certainly be historic. Even before this disclosure dropped, the movement to invalidate the decision of a plurality of GOP primary voters had hundreds of supporters within the community of convention delegates. All this movement lacked was a leader. The positioning among prospective candidates for that role has begun.

“I think historically, not just this year, delegates are and should be able to vote the way they see fit,” said Walker this week. Walker, a delegate himself, pledged to cast his first-round ballot for Ted Cruz.

Having promised to vote for Trump when he became the presumptive nominee, Walker’s candid statement represents a walk-back just short of an un-endorsement. And according to two sources who spoke with CNN, the Badger State governor is “intrigued” by the prospect of emerging from a balloting process as the consensus figure to represent the party in November.

As a declared 2016 candidate, Walker was vetted in the press and actually spent a brief period in the winter of 2015 at the top of the polls before a series of blunders on policy and a wildly mismanaged campaign compelled him to drop out months before a single vote was cast. In addition, Republican primary voters were looking for star power and stage presence—two qualities Walker cannot be said to possess. And yet for this very reason, the Wisconsin governor might present the starkest contrast to Donald Trump of any of the GOP’s prospective Trump replacements (with the possible exception of former Indiana Governor Mitch Daniels).

It must be said that the prospect of a coup at the convention remains exceedingly unlikely. Republicans who are desperate for reassurance that Trump will not decimate the party in November will be able to find it if they look hard enough. Still, by lending legitimacy to the “conscience clause” campaign, Walker has inserted himself into a process from which he may emerge as something far more than just a supporter.