At least 1,000 people rallied Sunday against Hillary Clinton's likely selection as the Democratic presidential nominee here, and thousands more are expected to join in Monday as the Democratic National Convention starts. Some of those activists say they will not vote for Clinton under any circumstances, a feeling further compounded by leaked emails that showed some within the party at least considered subverting Sanders.
As Clinton appears set to lock up the nomination this week, those Sanders supporters will soon have to decide whether helping to defeat Trump is worth the cost of backing Clinton. While it is unclear how many Democrats may refuse to vote for Clinton, it poses a risk to her in what has become a tighter race with Republican nominee Trump.
"This is going to be the election of voting against someone as opposed to voting for someone. It's not really going to be about whether Hillary is going to get them to vote for her but whether Trump will make them vote because they're so scared of him," said Jessica Levinson, a professor at Loyola Law School and vice president of the Los Angeles Ethics Commission.
Sanders, an independent from Vermont who caucuses with Democrats in the Senate, energized millions of Democratic and independent voters in the primaries. He drove his Clinton challenge with rhetoric against Wall Street wealth and an entrenched political establishment, which many supporters feel is embodied by Clinton.
A common chant from protesters this week is "Hell no, DNC! We won't vote for Hillary!" The Clinton campaign did not immediately respond to a request for comment.
Some progressive voters feel Clinton stands for the values Sanders opposes. Others think Sanders never had a chance and the Democratic Party effectively crowned Clinton.
The former secretary of state and first lady's "establishment" reputation and handling of classified information on a private email server has prompted criticism from across the political spectrum. The WikiLeaks release of Democratic Party emails has only exacerbated the feeling among some that her nomination was inevitable.
Sanders' recent endorsement of Clinton, in which he pledged to do whatever necessary to beat the bombastic Trump, might have swayed some voters to Clinton. But others say they will still support Sanders and even consider a mass de-registration from the Democratic Party if he does not secure the nomination this week. Sanders did not concede when he endorsed Clinton.
"'Bernie or Bust' is as strong as ever, if not stronger. If the Democratic Party does not select him, we are having a de-registration party at the DNC," said doctor and activist Laurie Cestnick, an organizer of Monday's "Occupy DNC" rally.
Sanders garnered roughly 12 million votes in the Democratic primary, compared with nearly 16 million for Clinton. The former secretary of state won the contest both for pledged delegates and so-called superdelegates," common recipients of Sanders' ire.
Cestnick and another activist, Billy Taylor, who organized one of Sunday's protests, said they could not be convinced to vote for Clinton.
"There is absolutely nothing that anyone can tell me about Hillary Clinton. I know enough. There is nothing in this world that will make me vote for Hillary," said Taylor, executive director at Philly.fyi.
Taylor and Cestnick said some "Never Hillary" voters will either write in Sanders, vote for the Green Party's Jill Stein, or abstain altogether.
Voting third party or not voting at all could lead Sanders supporters to hurting "the policies they care about," Loyola's Levinson said. She said there is a "gulf" between Sanders and Trump on issues like income inequality and affordable health care and college.
Many or most of those who voted for Sanders in the primaries could still support Clinton in the general election. Democrats have tried to cast Trump as a dangerous and divisive candidate, and many on the left see him as that.
But the lingering resistance to Clinton may sap her of votes in what could prove a close contest with Trump. Clinton and Trump are almost in a dead heat in an average of recent polls that includes Stein and Libertarian Party candidate Gary Johnson, according to RealClearPolitics.
Trump has received a recent bump since the GOP convention in Cleveland last week.
Levinson said apathy may be Clinton's biggest fear at this point. If polls show her in the lead by late October, some staunch Sanders supporters may be more inclined to vote third party rather than for Clinton.