The sect of the GOP that is uncomfortable with Donald Trump as the party’s presumptive nominee are formulating one last plan to stop the Republican candidate: staging an all-out delegate revolt at the Republican National Convention in July. The radical idea stems from a continuing disapproval among some conservative stalwarts with how Trump is running his campaign.

As the Democratic Party’s heaviest endorsers, including President Barack Obama, Vice President Joe Biden and Massachusetts Sen. Elizabeth Warren, line up behind Hillary Clinton, Republicans are still in-fighting and criticizing their own nominee. Trump has recently stated he has become fed up with how GOP leaders are treating him.

Conservative commentator and Weekly Standard editor Bill Kristol has been actively seeking a candidate to mount an independent bid against Trump. He tried no-name conservative lawyer David French, but that did not catch fire. “I’ve been focused on independent candidacy, & still am. But struck by sudden level of interest in possible delegate revolt at convention,” Kristol tweeted. He added: “A Convention of Conscience in Cleveland would be quite something. Made easier by fact Trump only won minority of total primary votes anyway.”

The rules created by the previous convention, which govern in 2016 until delegates pass a new line of rules, state that even if a delegate casts a ballot for a candidate other than one they are bound to, the convention secretary will record their bound vote. In order to adapt that rule, the 112 delegates (two from each state and territory) on the Rules Committee would have to bypass different rules and bring those to the floor of the convention, where a majority of delegates present would then have to approve them. How likely is this? Very unlikely. Is it possible though? Yes.