2020 primary takeaways: Joe Biden's nomination to lose

Democratic presidential candidate former Vice President Joe Biden enters a campaign event in Columbus, Ohio, Tuesday, March 10, 2020. (AP Photo/Paul Vernon)
Democratic presidential candidate former Vice President Joe Biden enters a campaign event in Columbus, Ohio, Tuesday, March 10, 2020. (AP Photo/Paul Vernon)

WASHINGTON, D.C. – Joe Biden's path to the Democratic presidential nomination widened significantly Tuesday with commanding victories in Mississippi, Missouri and Michigan, a state that his rival Bernie Sanders won four years ago. Key takeaways:

IT'S BIDEN'S NOMINATION TO LOSE

Biden has become the reliable Buick of this race.

His momentum accelerated as he broadened his delegate lead over Sanders with a series of decisive victories. The former vice president's solid win in Michigan came in a state Sanders was depending on both to bolster his case going forward and for the practical delegate math involved. He came into the day about 96 delegates behind Biden, and Michigan was his best shot at preventing that lead from getting any wider. (Democrats require 1,991 delegates for nomination.)

As it is, Sanders lost a big state where his upset of Hillary Clinton four years ago gave him reason to continue his presidential bid through the end the nominating calendar in June. This time, the first round of voting after Super Tuesday ended the same way as last week's surprise outcome: with a Biden celebration and an increasingly steep climb for Sanders.

Biden isn't just leaning on his base of African Americans. AP VoteCast surveys in Michigan and Missouri also show he topped Sanders in suburbs and, notably, across small-town and rural counties, where Sanders had led Clinton in 2016.

“We need you, we want you, and there’s a place in our campaign for each of you," Biden said Tuesday night. "I want to thank Bernie Sanders and his supporters for their tireless energy and their passion. We share a common goal, and together we’ll beat Donald Trump.”

Sanders' bad March can be explained this way: Biden's net delegate gains out of Alabama last week and Mississippi on Tuesday — two Republican-dominated states — essentially cancel out the delegate advantage that Sanders pulled out of California, which has the largest delegate trove.