Of all the Republican politicians, operatives, and commentators who have been emasculated by Donald Trump, the senators who returned there after he bested them in 2016 are the most obsequious.

This ignominious list of once-bold, and now house-trained, Republicans includes Lindsey Graham, Ted Cruz, Marco Rubio, and Rand Paul. They’re broken in now, like an old pair of jeans with no shape of their own.

On the campaign trail, Rand called Trump a “delusional narcissist” and a “fake conservative,” and Trump mocked his height. Rubio mocked Trump’s small hand size and called Trump a “con artist,” and Trump eviscerated “Lil Marco.” Graham said Trump was a “kook,” “crazy,” and “unfit for office,” and Trump gave out Graham’s personal cellphone number on national television. Cruz said Trump was a “pathological liar,” a “narcissist,” and a “serial philanderer,” and Trump and basically called Cruz’s wife ugly—while accusing Cruz’s dad of being involved in the Kennedy assassination.

It worked. At a rally earlier this week, Paul—a man who was once honored at something called the Whistleblower Summit for Civil and Human Rights—called on the media to unmask the Ukraine whistleblower.

Among Paul’s erroneous assertions was the notion that, “Enshrined in the Sixth Amendment is the right to confront your accuser.” Even Andrew McCarthy—a conservative writer and lawyer who doesn’t think Trump’s actions are impeachable (despite having written a book making the case for Barack Obama’s impeachment)—is pushing back, noting that “Impeachment is neither a criminal trial nor a legal process, so the president does not have the constitutional right to confront his accuser.”

Trying to “out” a whistleblower is pretty low. Still, in the race to the bottom, Paul can’t hold a candle to Lindsey Graham, the former best friend of John McCain and House impeachment manager during Bill Clinton’s impeachment, turned Trump doormat.

Earlier this week, faced with mounting evidence that Trump did, in fact, meet the burden of proof that he set for establishing a quid pro quo, Graham simply declared that "I'm not going to read these transcripts...The whole process is a joke… I’m not going to legitimize it.”

We all have to find ways to manage cognitive dissonance, and Graham’s way seems to be to bury his head in the sand. (Other recent Graham “arguments” include suggesting that Trump is too incompetent to engage in a quid pro quo, and that Gordon Sondland—a man who donated a million bucks to Trump’s inauguration—might be conspiring with Democrats.)

I could cite chapter and verse on all of these guys, but it’s probably not necessary to establish that Rubio and Cruz have, likewise, been tamed. Anyone who disagrees with their status as Trumpian minions need only familiarize themselves with the Google search function.

For whatever reason, the GOP’s leading hypocrites, the apple-polishing-est toadies, seem to be Trump’s vanquished primary opponents who returned to the U.S. Senate. (This phenomenon doesn’t seem to apply to people who didn’t return to their old jobs. Jeb Bush and John Kasich, for example, are Trump critics. Meanwhile, Cabinet secretaries like Rick Perry and Ben Carson have, for the most part, kept a low profile.)

What explains this?

First, unlike Jeb and Kasich, these guys still have political careers to worry about.

Second, there’s a sort of Stockholm Syndrome associated with having to return to your old job, having reached for the brass ring, only to have been humbled by someone who views himself as your “boss.”

I’m reminded of an episode of The Simpsons where Homer is forced to return to his old job at the Springfield nuclear power plant. When Mr. Burns’ receptionist finds out he is not a new applicant, he is made to crawl through a much smaller dog door that reads "supplicants."

After groveling to get his old job back, Homer's made to work at a desk facing a sign that reads: DON’T FORGET: YOU’RE HERE FOREVER.

In the Trump era, though, though these senators aren’t Homer Simpson. They’re Waylon Smithers, endlessly debasing themselves to please the boss.

It’s no easy task to rank Republican ass-kissers given how many Republicans have abandoned their principles to please him (see Mark Meadows, Jim Jordan, et al.).

Still, the 2016 candidates who lost to Trump—and then returned to the senate—appear to be the biggest brownnosers of them all.