Mitt Romney has announced that he’ll be giving a speech Thursday to discuss the state of the GOP race with a focus on Donald Trump.

Last week, Romney suggested there could be a possible “bombshell” in Trump’s taxes. On Monday he criticized Trump’s response over the weekend to a question about the KKK, calling it “disqualifying.”

A disqualifying & disgusting response by @realDonaldTrump to the KKK. His coddling of repugnant bigotry is not in the character of America.

— Mitt Romney (@MittRomney) February 29, 2016

With that as recent history, you won’t be surprised to learn Romney intends to lay out the case against nominating Trump when he speaks at the University of Utah tomorrow. Bloomberg Politics reports:

With Trump’s convincing victories on Tuesday, the single biggest day of voting in the Republican race, Romney was motivated to make a more formal case against him in hopes of keeping him from coalescing more support, according to a Republican source familiar with Romney’s plans. Romney has voiced criticism for Trump in recent months, including his attack last week on the New York businessman’s refusal to release his tax returns.

Romney doesn’t believe Trump is the right person to lead the party, the Republican source said. A number of mainstream Republicans are falling in line with Trump, and Romney wants to speak up before more people go that route, the source said.

While making the case against Trump at the Hinckley Institute of Politics Student Forum at the University of Utah, Romney will not endorse one of his opponents, two people familiar with the former Massachusetts governor’s plans said. Romney will, however, praise Florida Senator Marco Rubio, Texas Senator Ted Cruz, and Ohio Governor John Kasich. Romney’s comments will be focused on “the state of the race,” likely echoing past criticism of Trump for failing to release his tax returns, and not decisively distancing himself from the Ku Klux Klan.

Trump is not waiting to hear what Romney has to say. He lashed out at Romney on Twitter Wednesday afternoon:

https://twitter.com/realDonaldTrump/status/705174362530430976

https://twitter.com/realDonaldTrump/status/705174403164860416

Trump supporters on Twitter have started circulating video of Romney praising Trump:

This video comes from February 2012 when Trump was endorsing Romney for President. While it’s true Romney is reversing himself on Trump, it’s also true that Trump has reversed himself on Romney. Back in 2012 Trump said, “It’s my honor, real honor, and privilege to endorse Mitt Romney…Mitt is tough, he’s smart, he’s sharp. He’s not going to allow bad to continue to happen to this country that we all love.”

It’s hard to imagine this is going to have any impact on Trump. If the Pope’s suggestion that Trump is not a real Christian had no discernible impact, how much is the word of a former politician who lost the last election going to matter? Trump will call Romney a loser a few more times and move on. Romney might be more effective if he were to endorse an alternative candidate. As it is he’s not throwing his support behind someone, he’s throwing it against someone. But he’s been doing that for a week already. Has it mattered so far?