The afternoon after Vermont Sen. Bernie Sanders pulled out a surprise upset and narrowly beat Hillary Clinton in Tuesday’s Michigan primary, the former secretary of state's campaign stressed that the delegate gap between the two candidates has only grown and the path to the nomination comes down to a simple calculus: math.

“Between the two contests last night, more than 100,000 more Americans cast their ballots for Hillary Clinton. In total now more than 4.8 million Americans have supported Hillary Clinton,” Robby Mook, Clinton’s campaign manager, said Wednesday in a press call with reporters. Sanders would need to pull off “lopsided margins” in coming contests to catch up and win the nomination, he added.

“For that reason, we are confident that we are nearing the point where our delegate lead will become insurmountable,” Mook said.

While Sanders beat Clinton in Michigan 49.8 percent to 48.3 percent Tuesday night, the contest in Mississippi was nowhere near as close. In the Magnolia State, Clinton beat Sanders 82.6 percent to 16.5 percent, a lead that gives her 29 delegates to his 4 in the state, according to a recent tally. The Michigan tally, on the other hand, gives Sanders 65, compared with Clinton’s 58 there. Clinton leads with pledged delegates 745 to 540.

The candidates head to five contests next week: Florida, North Carolina, Illinois, Missouri and Ohio. Mook said the campaign plans continue the strategy it has been using — “national style,” which includes operations in all of the states that are voting. He described the Sanders campaign as one that is “focused on picking off” viable states instead of running competitive campaigns in every one.

The Sanders campaign did not immediately respond to a request for comment or reaction to Mook’s statements Wednesday.

RTS9XHQ Hillary Clinton speaks to supporters in Cleveland about the primary voting results in Michigan and Mississippi, March 8, 2016. Photo: Reuters