Sen. Jeff Sessions
of Alabama endorsed Donald Trump tonight. Sessions, an anti-immigration hard liner, donned a red “Make America Great Again” hat at a rally in Madison, Alabama. The hat helped him think of a good line. “At this time in America’s history, we need to make America great again!” Sessions said. 

Gov. Chris Christie of New Jersey and Gov. Paul LePage of Maine recently gave Trump his first endorsements from sitting governors. Now comes the stamp of approval from a U.S. Senator. 

This is a big deal for a few reasons: First of all, the trickle of endorsements from GOP lawmakers gives Trump’s candidacy legitimacy. He is well positioned to start running up the score in the delegate count, but if he wants to inch up from his floor among GOP voters (likely around a third of the vote in most states) and get past 50 percent, he needs to convince voters who might generally like him but be uncertain about how serious his campaign is. Endorsements from major figures in the party help.

Meanwhile, Sessions in particular will aid Trump in Alabama on Tuesday, a state where he has a big lead but Marco Rubio has been trying to gain ground. This is also a blow to Ted Cruz, who had hopes that Sessions would endorse him. 

And here’s the big one: Sessions is a hero among anti-immigration activists within the GOP base. Every time immigration comes up in a debate, Cruz says he stood with Sessions (while Rubio ganged with Democrats on the immigration reform bill). Now Trump will throw it back in his face: Sessions endorsed me. Sessions also gives substantive heft to the immigration issue that Trump has mostly tackled with one-liners and goofy promises about the wall (Sessions has advised Trump on immigration policy in the past). If you want to establish that you’re tough on immigration, there’s probably no better way to do it than an endorsement from Sessions. This is a nightmare scenario for Rubio: immigration remains the issue on which his heresies could be a real weak point among Tea Party voters. Trump’s endorsement from Sessions gives him a news cycle to hammer Rubio on that point and positions Trump even more as the candidate of choice for any GOP voter who cares most about opposition to immigration reform. 

Trump also got another endorsement over the weekend from former Arizona Gov. Jan Brewer, another hero to the anti-immigration crowd. Like Sessions, she gives Trump both a mainstream stamp of approval and also helps establish his anti-immigration bona fides. 

The Donald has also made headlines this weekend for a Mussolini quote and for declining to repudiate endorsements from the KKK and its former leaders — “I know nothing about David Duke, I know nothing about white supremacists,” he said in an interview. So a typical weekend.

Here’s Robert Costa of the Washington Post (and formerly National Review), who knows GOP politics as well as anyone: 

Here’s Vox on what the Sessions endorsement means and why it makes sense (Sessions was the “forefather of Trump’s immigration positions” and “Sessions, like Trump, has gotten in trouble for not disowning the Ku Klux Klan”). Sessions has an ugly history with race, including saying he thought the Klan was okay until he realized that some of them were pot smokers. He said he was joking.  

Sessions’ full name is Jefferson Beauregard Sessions III. Just as a side note. 

postscript: Trump now has more endorsements from the United States Senate than Sen. Ted Cruz. I’m sure we’ll here about that a time or ten in the next debate.