During the 2016 presidential campaign, after his own candidacy failed, Sen. Lindsey Graham’s (R-S.C.) principal focus was on stopping Donald Trump from becoming his party’s nominee. Two years ago at this time, the Republican senator described Trump as a “race-baiting, xenophobic, religious bigot” who should be told to “go to hell.”

After Trump became president anyway, Graham appeared well positioned to be an intra-party thorn in the White House’s side, mocking Trump’s dismissal of Russia’s attack on the American elections, for example. For his part, the president was publicly admonishing Graham as recently as August.

The two have evidently put their differences behind them. The South Carolinian, who now complains about pundits criticizing the president in the same ways he used to, has become one of Trump’s high-profile cheerleaders.

Indeed, Graham’s Twitter feed took a turn toward the bizarre in recent days, promoting conspiracy theories and anti-Clinton nonsense. TPM’s Josh Marshall explained yesterday:

Note here the things that Graham is including in his call. They range from things that are fairly unreasonable or without significant merit to things that are totally crazy. He is asking for a Special Counsel to reinvestigate Clinton’s private server, the Uranium One story, which is completely ludicrous, and anti-GOP bias at the FBI, which is not only factually nonsensical but seems intended to lay the groundwork for ideological purges of the primary national law enforcement agency which already has a very Republican-leaning political culture.

One might expect some of Graham’s over-the-top rhetoric from a conservative pundit or a House Freedom Caucus member, but the senator is supposed to be above such things.

Except he’s not.

Even on the Trump-Russia scandal, which Graham used to take quite seriously, the senator’s posture has changed. Now he apparently intends to push for a special counsel probe of “ALL THINGS 2016 – not just Trump and Russia.”

It’s difficult to know what’s driving this. Perhaps Trump is open to new military interventions abroad and Graham is cozying up to the president to help guide his hand. Maybe Graham is worried about a primary challenge in South Carolina in 2020. Perhaps party donors are pushing members to be more doctrinaire in their partisanship. Maybe Graham wants a cabinet post.

Whatever the rationale, those looking for Republican senators unafraid to buck the Trump White House should probably stop looking at Lindsey Graham.

Postscript: As if to prove the point about his new chumminess with the president, Graham tweeted yesterday how impressed he was the “spectacular” Trump International Golf Club, and how much he enjoyed his “great day of fun” with Trump.