How Sasse responds — he has a book coming out three weeks before the midterm elections and has quietly launched a new political non-profit group, fueling speculation that he might launch a Hail Mary bid for president rather than seek another term in the Senate — promises to be the next intra-GOP drama.

Behind the scenes, the president has stewed over Sasse’s recurring jabs, according to several people familiar with his thinking on the matter. After the 2016 campaign – in which Sasse refused to vote for Trump and compared the New York City mogul to white supremacist David Duke – Trump had a conversation with a GOP senator in which he referred to Sasse as “that guy” and said he’d like to see the Nebraska Republican “go away.”…

One of Sasse’s friends, White House Legislative Affairs Director Marc Short, has worked to smooth things over with the president. The Trump aide has brokered meetings between the two in the hopes they’ll get to know one another better, while encouraging Sasse to give Trump a heads-up before he’s about to publicly criticize him.