Donald Trump at a National Press Club luncheon in May. (Jewel Samad/AFP/Getty Images)

If there was a master class in how not to conduct yourself as a politician, it would look a lot like Donald Trump.

Trump, who fashions himself a potential 2016 presidential candidate and ally to the tea party, has turned himself into little more than a punchline these days. What’s amazing is that he keeps getting invited to gatherings like the Iowa Freedom Summit two weeks ago – an opportunity he used to rag on Jeb Bush and Mitt Romney.

Trump will also be at the Iowa Agricultural Summit in early March and the Conservative Political Action Conference later this month, per Breitbart.

It’s even more amazing when you consider this: Republicans hate Donald Trump.

Yes, the guy who was leading the GOP primary polls in the early part of the 2012 campaign -- almost exactly four years ago now -- is nothing shy of a pariah, even among the most devoted early primary and caucus voters.

A Bloomberg/Des Moines Register poll of the Iowa caucuses over the weekend showed Trump was viewed unfavorably by 68 percent of likely caucus-goers, compared to 26 percent who liked him. Of the 68 percent who disliked him, nearly half viewed him "very unfavorably."

A new University of New Hampshire poll of the New Hampshire primary, meanwhile, shows basically the same thing there. While 69 percent have an unfavorable opinion of Trump, just 19 percent have a favorable one.

These numbers, we would stress, are among Republicans.

None of this is to suggest that Trump is still politically relevant. Almost nobody takes him seriously when he says he might run for president this time. But this is a guy whose endorsement Mitt Romney promoted in the 2012 primaries – a guy who was supposed to be the tea party’s guy.

Now, it seems, he’s not even welcome among groups like the one Rep. Steve King (R-Iowa) assembled for the Freedom Summit.

It’s probably safe for the GOP to cut Trump loose. In fact, it would almost definitely help.

This post was updated at 3:59 p.m. with news of Trump's CPAC appearance.