Mattis expected to be tapped by President Hillary Clinton. He got Trump instead.

In a series of meetings with colleagues at the beginning of the administration, Mattis said he was originally surprised to get a call from the Trump team asking him to take the post of defense secretary, according to two sources with who attended those meetings. He told several people that had Clinton won the election, he thought he would have agreed to serve on her team.

According to three former Clinton campaign advisers, the former secretary of state and Mattis had a very positive relationship, predating the campaign. Though no final decisions were made on who would serve as the defense secretary in a Clinton administration that never happened, Mattis was still someone Team Hillary regarded highly.

Mattis and senior Clinton staffers stayed in touch during the presidential campaign, and the former advisers said they solicited his advice on foreign policy and national security matters. The 2016 Clinton team even tried to recruit Mattis to publicly endorse Hillary for president against Trump. According to two of these sources, he politely declined, though conveyed to the campaign his respect for Clinton.