He is a vengeful god, but also at times a merciful god. Especially when you keep your mouth shut and vote with him 97.6 percent of the time.

POTUS had the opportunity here to whack another prominent right-wing critic, like he did to Mark Sanford just 10 days ago. Remember this? October 8, 2016, the day the “Access Hollywood” tape dropped:

Donald Trump's behavior makes him unacceptable as a candidate for president, and I won't vote for him.

Full statement: pic.twitter.com/Ge7GU1TSvm

— Martha Roby (@MarthaRobyAL) October 8, 2016

Two weeks later, with Trump recovering in the polls, his fans confronted her at a campaign event in Alabama. One invited her to cast the proverbial first stone, reminding her that we’re all sinners and therefore we … should elect a guy who talks about “grabbing women by the p***y,” I guess. Roby remained defiant: “I do not want Hillary Clinton to be president of the United States, but I cannot look my children in the eye, Margaret and George, and justify a vote for a man who promotes and boasts about sexually assaulting women.” What kind of Christian is she?

Alabama is Alabama so she ended up winning her race, albeit by “only” eight points. The real reckoning came earlier this month when she faced Republican primary voters in her district for the first time since 2016. It should have been an easy one: She was pitted against Bobby Bright, a former mayor of Montgomery who was elected to Congress in 2009 — as a Democrat. Roby the Republican versus a Democratic wolf in sheep’s clothing? No contest. But it was a contest, thanks to long memories about her heresies against Trump two years ago. She failed to get 50 percent in the primary and ended up in a runoff against Bright to be held next month. Time for POTUS to exact revenge by administering the coup de grace and endorsing Bright, right?

Nope.

https://twitter.com/realDonaldTrump/status/1010126805850902528

What’s the difference between Roby and Sanford? Well, a few things. Roby’s voted with Trump far more often than Sanford has. He’s backed the president’s agenda 70 percent of the time, a poor rate for a Republican. Roby’s opponent, as noted, is a former Democrat whereas Sanford’s was a Republican who spent the primary praising POTUS. It’s obviously easier for Trump to back the latter than the former. Roby’s Alabama pedigree may also have influenced his decision. Having already been rebuked by Alabamians twice, once with his endorsement of Luther Strange and then again with his endorsement of Roy Moore, Trump may have worried about looking weak by backing Bright and then seeing Roby squeak through to victory anyway, as unlikely as that would be.

But the main difference between her and Sanford? Roby’s kissed a lot of presidential ass to try to make amends for unendorsing Trump in 2016. Nearly a year ago Politico published a story on Trump’s “enemies list” adorned with a photo of Roby — but noting that she was already months into a charm offensive aimed at healing the rift with him:

Since the inauguration, she has gone to the White House four times to attend Trump-hosted events and on two other occasions to meet with his daughter Ivanka — at the White House’s invitation. During the Rose Garden celebration following the House’s passage of the health care bill, the four-term congresswoman offered the president a personal compliment while shaking his hand: “Good job,” she told him, according to a source close to Roby who was briefed on the exchange.

White House officials have taken notice of Roby’s efforts to make amends and view her efforts with some skepticism. While in the Oval Office for a NASA bill signing in March, Roby sidled up next to Trump — putting her front-and-center for the photo-op. Behind her push for the president’s approval is a stark political reality: She is facing a fierce primary challenge from a Trump stalwart who has turned her past opposition to the president into the focal point of his campaign…

Two White House aides say the president now relishes that some of those who crossed him, like Roby, are scrambling to get in his good graces.

Per Politico, she posted a Facebook video shortly after he was sworn in last year stressing that “I sat in the Oval Office and looked the President in the eye and told him I was with him” on ObamaCare repeal. Still, POTUS was reportedly on the fence about whether to endorse her or not.

The deciding factor may have been a little arm-twisting from Paul Ryan:

More: I'm told that Trump initially needed some convincing about endorsing Roby, per 2 ppl close to WH. Both McCarthy and Ryan were involved in getting POTUS's support for Roby, an ally of House GOP leadership

— Alex Isenstadt (@politicoalex) June 22, 2018

It may be that Sanford’s demise helped save Roby. House Republicans weren’t thrilled to see him go, less so to see Trump mock him and his defeat at a meeting with them earlier this week. Ryan may have dialed POTUS up and warned him that it would be in his own interest not to make any further enemies in the caucus by liquidating Roby too. He already put the fear of God into them by blowing up Sanford; now it was time for a show of magnanimity, to remind them that he’s willing to forgive a moment of disloyalty in the past if they’re wiling to pledge loyalty to him going forward. To put it another way, Sanford is the stick and Roby is the carrot. Stay on Trump’s good side and you have nothing to fear. Scorn him and pay the price.

Here she is in late October 2016, before her long campaign towards today’s endorsement began.