Sen. Bernie Sanders (I-Vt.) won Montana's Democratic primary on Tuesday, even though Democratic front-runner Hillary Clinton has already secured enough delegates to make her the party's presumptive nominee.
Montana has 21 Democratic delegates in play that are doled out proportionally, based on the vote tallies. The Montana primary took a back seat to Tuesday's contest in California, which had more delegates at stake -- 475 -- than any other state in the country.
But no amount of delegates for Sanders in Tuesday's six contests is enough to make up his shortfall, according to The Associated Press, which called the nomination for Clinton on Monday night after a survey of unpledged delegates determined that her lead was insurmountable.
Clinton currently has the support of the 2,383 delegates necessary to clinch the nomination. If she is officially nominated at the Democratic National Convention in Philadelphia next month, she will be the first woman ever to top a major party's presidential ticket.
Sanders, a self-described democratic socialist whose campaign has galvanized progressives around the country, has vowed to push on until Philadelphia, pointing out that unpledged superdelegates aren’t officially counted until they vote at the convention. Sanders and his followers have ripped the media for calling the race for Clinton.
"Our job from now until the convention is to convince those superdelegates that Bernie is by far the strongest candidate against [presumptive GOP nominee] Donald Trump," Michael Briggs, a Sanders spokesman, said in a statement.
Clinton said she was "flattered" by the AP's call, but still wanted to win as many delegates as possible on Tuesday.
Regardless of the delegate math, Tuesday's primaries matter for the sake of momentum. Primary losses to Sanders -- particularly in either of the delegate-rich states of California or New Jersey -- take some air out of Clinton's campaign as she tries to pivot to the general election. They also embolden Sanders' campaign and its followers to take their message as far as they can.
Although Republican voters headed to the polls in five states on Tuesday, Trump is the only Republican left standing. The real estate mogul has spent the week defending and amplifying racist comments he made about an Indiana judge handling a civil case against Trump University.