(CNN)Never underestimate the politician's agony at not being talked about for five minutes. That's one explanation for Ted Cruz's decision to endorse Donald Trump -- he may be yearning for a return to the national scene.

It's certainly a surprising move given the two men's personal history. Donald Trump called Cruz a liar, a Canadian, implied that his wife was unattractive and hinted that his father might have been linked to the assassination of Jack Kennedy. Saint Cruz took revenge in his convention speech by withholding an endorsement. It was the highest point in his career. He should've stayed up there.

Instead, he has prostrated himself before Trump on Facebook. Why? Objectively, it makes some sense. If Trump was 10 points behind Clinton, Cruz would be wise to sit out the election and say "I told you so." The party would owe him some respect. But if Trump narrowly loses to Clinton, then Cruz could be blamed for the defeat -- with repercussions for his own re-election effort in Texas. Worse, if Trump actually wins -- Cruz will be frozen out of GOP politics for four, maybe even eight years. That's a big gamble to take.

But this is Cruz's problem: he's all tactics, no strategy. It seems smart to play the odds and come out for Trump just before the first debate -- it gets him attention and gets him into the big guy's good books. But when the historians come to tell the story of this election the endorsement is going to look like an odd mix of craven and vain. One does not assert statesmanship by selling one's soul in public.