Former Chicago mayor Rahm Emanuel, whose nomination to become ambassador to Japan has angered liberal activists, has clinched the votes of at least three Republican senators, giving him an important buffer against possible Democratic defections and boosting his chances of winning confirmation in the evenly divided Senate.

Emanuel, who has held powerful positions in government for three decades, is waging an aggressive behind-the-scenes effort to secure votes from Democrats and Republicans, according to people with knowledge of the situation. Among his earliest coups are Sen. Lindsey O. Graham (R-S.C.), a close ally of former president Donald Trump; Sen. Roy Blunt (R-Mo.), the fourth-ranking GOP senator, who has opted not to seek reelection next year; and Sen. Susan Collins (R-Maine), a centrist fresh off winning a fifth term.

“I haven’t used the word ‘diplomatic’ in a sentence describing Rahm Emanuel very often,” Blunt said of the nominee, who is known for his brash personality. “But in this case, I think he will meet that standard.”

Blunt said he expects “several Republicans” will join him in voting for Emanuel and added, “In a 50-50 Senate, it doesn’t take a lot of Republicans to get this job done.”