For a while in 2012, I enthusiastically supported Rick Santorum for president. He made some blunders that forced me to reevaluate his viability, and his blend of fiscal, social, and defense conservatism was largely obsolete this time around thanks to Ted Cruz, but I always retained a soft spot for Rick, thanks to him being a pro-life, pro-marriage champion, rock-solid on national defense, and having the strongest immigration record in the 2016 field.

Well, I’m sorry to say my respect for the man is gone for good, now that he’s decided to endorse Marco Rubio, and in doing so signaled that the values he’s spent his career fighting for aren’t so important after all.

During his latest (and hopefully final) presidential campaign, Santorum’s message was that he was the truest true conservative in the race, so much so that Cruz just wasn’t strong enough on same-sex marriage (the National Organization for Marriage disagrees) or immigration (Jeff Sessions, Tom Tancredo, and Steve King disagree) to measure up to him.

So what does he do once he drops out? Endorse the worst major candidate on both of those issues.

Rubio’s Gang of 8 treachery is the stuff of legend by now, and even today he still supports citizenship for illegals. So logically, he should be utterly intolerable to a guy who specifically bashed Rubio over amnesty and used to say that Republicans joined Democrats in their support for open borders because “neither party has an interest in helping the American worker,” recognized that Democrats were using it to import voters, and condemned amnesty as “a slap in the face of every working American.” I guess Rick’s decided that if he can’t be president, he might as well get in on the slapping.

But amnesty is the Rubio sin everyone knows about. His weakness on defending marriage has gotten much less attention. Despite a reputation as a social conservative that comes from a combination of being reasonably good on abortion and not-so-subtly name-dropping Jesus, Rubio is virtually useless on same-sex marriage.

Sure, he recognizes that there’s no constitutional right to same-sex marriage and that that it’s a vital cultural institution. But he opposes actually doing anything about it:

Republican presidential candidate Marco Rubio said Wednesday he would oppose a constitutional amendment allowing states to ban same-sex marriage after the Supreme legalized it nationwide, even though he disagrees with the landmark 5-4 decision.

“I don’t support a constitutional amendment. I don’t believe the federal government should be in the marriage regulation business,” the Florida senator told reporters after a speech the Cedar Rapids Country Club in Iowa.

“We can continue to disagree with it. Perhaps a future court will change that decision, in much the same way as it’s changed other decisions in the past. But my opinion is unchanged, that marriage should continue to be defined as one man and one woman. The decision is what it is, and that’s what we’ll live under.”

Note that Rubio isn’t merely rejecting an amendment to enshrine marriage’s definition in the Constitution—he’s saying he doesn’t even support one to restore the states’ right to vote on the subject. Nor has he suggested any alternative means of reversing the Supreme Court’s decision, as Cruz has (Cruz also supports a Marriage Federalism Amendment, plus specific reforms to counter judicial intervention. I’d prefer the stronger amendment, but recognize it’s strategically very tricky).

This is horribly misguided from my perspective, but from Santorum’s own, it’s downright indefensible. How do you bash Cruz for applying federalism to marriage, only to endorse a guy who has a weaker version of the very same position?

How do you reject the candidate closest to yourself on substance in favor of one who embodies the very GOP failings you’ve condemned as major problems?

There’s no way to reconcile this endorsement with Santorum’s pitch for his own candidacy. There are only two explanations that I can see: either he’s sick of being stuck out in the cold for so long and thinks the way back inside is to suck up to the pick of “respectable” Republicans (“taking one for the team,” in Rick-speak), or he’s so bitter that he can’t recapture the voters that flocked to him last time because Cruz made him obsolete that he’s snubbing Cruz purely out of spite.

Either way, it’s proof that voters were right to ignore Rick Santorum before, and that he will remain unworthy of voters’ consideration in any future vanity campaign.