Everyone is buzzing today about Mitt Romney’s op-ed criticizing Trump in the Bezos Bulletin. (This, after seeking Trump’s endorsement for the Senate in Utah, and treating with Trump in 2016 to be secretary of state.) The piece has that “more-in-sorrow-than-anger” tone that Trump’s crude manners are unbecoming of a president, and may degrade our democratic culture.

Perhaps this is so. I’m less interested in becoming the 10,000th voice on this issue and more interested in drawing attention to just one paragraph in the article that cries out for closer notice:

It is not that all of the president’s policies have been misguided. He was right to align U.S. corporate taxes with those of global competitors, to strip out excessive regulations, to crack down on China’s unfair trade practices, to reform criminal justice and to appoint conservative judges. These are policies mainstream Republicans have promoted for years.

I boldfaced “promoted” because Romney has unwittingly provided the devastating argument against his style of Republicanism. Yes, it is quite true that nearly all Republican presidential candidates—and presidents—have promoted tax reform, lower regulation, getting tough with China, and appointing better judges (and add in moving the U.S. embassy to Jerusalem), if by “promoted” you mean giving lip service to the ideas.

None of them have delivered on these “promoted” ideas (Reagan excepted, of course). The two presidents Bush botched judicial appointments, extended regulation, delivered little in the way of serious tax or spending reform, and did nothing serious with regard to China. I wish Romney had defeated Obama in 2012, but does anyone think this Massachusetts technocrat, who gave us the state-level version of Obamacare in the Bay State, signed up for a regional climate change cap-and-trade scheme, who appointed the egregious Gina McCarthy (Obama’s second EPA administrator) to be his environmental adviser, and appointed state judges who struck the first judicial blows for same-sex marriage, would have governed as a serious conservative had he won?

The point is, Trump has proved that “mainstream Republicanism” was a colossal failure. Whereas Bush-Romney Republicans “promoted” good ideas, Trump has delivered on them.

I’ll restate once again that I think Trump is, in Wall Street terms, a “high-beta presidency”—high risk, high reward. I wish he was more prudent and measured in the fights he picks and how he conducts himself. He remains his own worst enemy. I fear Trump’s presidency could end disastrously for conservatism. But in the meantime he has mounted the most vigorous challenge to liberalism of anyone since Reagan, under much more difficult political circumstances. We know what we’re going to get from Trump. From Romney, Jeb Bush, or John Kasich, we have no such confidence. Romney should just get to work at being a good senator, and stop the posturing. Or to paraphrase Don Rumsfeld’s most famous remark, we have to go into political battle with the president we have, rather than the president we wish he had.