Ted Cruz and Donald Trump are, not surprisingly, now in a total war. One school of thought is that Cruz made a mistake in cozying up to Trump for so long now that The Donald is lambasting him in the harshest and most demagogic terms. I don’t think that’s right. Even though Cruz’s “friendship” was transparently insincere–and often cringe-inducing–it was very shrewd, and the timing of the break-up is too. It was very unlikely that the truce could last forever, and the timing of the open hostilities means that Cruz can blame Trump for firing the first shot (the Canadian stuff) and, more importantly, attack Trump from a much stronger political position.

With his surge over the last month or so, Cruz has amassed an extraordinary reserve of credibility on the right. A recent poll in Iowa had him at 91-6 favorable-unfavorable among tea partiers. If anyone has the standing to make the case against Donald Trump, it is Ted Cruz. And he won’t be making a “golly, Donald, why can’t you be nicer?” case against Trump, but a hard-hitting conservative one (and while a divided and feckless establishment, such as it is, watches from the sidelines).

If there was any tactical error here it was on the part of Donald Trump. It has been pretty clear for a long time that Cruz had great potential in Iowa, but back when Trump could have dropped a bomb on Cruz before he took off, the mogul was either taken in by Cruz’s submissiveness, or willing to play along with the terms of their faux friendship.