Why Bernie bros believe the Democratic primary is rigged against Sanders

Michael Bloomberg’s abrupt exit from the Democratic presidential race opened a clear path to the nomination for former Vice President Joseph R. Biden, who has harnessed a surge of anti-Trump energy in the Democratic Party to block the far-left movement of Sen. Bernard Sanders.

After a disappointing Super Tuesday performance, the Vermont senator sounded familiar themes, describing his campaign as a rejection of the billionaire class epitomized by Mr. Bloomberg and the Democratic Party establishment that rallied around Mr. Biden. Here’s why Sanders’ fans believe the primary is rigged against their candidate:

• Mr. Biden received last-minute pre-Super Tuesday support from former rivals such as ex-Rep. Beto O’Rourke, Sen. Amy Klobuchar and former South Bend, Indiana, Mayor Pete Buttigieg, who reportedly received a persuasive phone call from former President Barack Obama.
• Sen. Elizabeth Warren of Massachusetts, who targets the same progressive voters as Mr. Sanders, has stayed in the race despite a stink bomb Super Tuesday, prompting the hashtag WarrenDropOut to trend on Twitter. She finally quit the race Thursday.
• Mr. Bloomberg, a former New York City mayor, spent $500 million trying to stop him, then threw his support behind Mr. Biden after quitting the race the day after Super Tuesday.
• The Big Tent Project Fund, an outside “dark money” group backing moderate Democrats, has been running anti-Sanders ads.
• The Democratic Party’s superdelegates have begun aligning themselves with Mr. Biden to block Mr. Sanders from securing the nomination at the July convention in Milwaukee.

“Joe is running a campaign which is obviously heavily supported by the corporate establishment,” Mr. Sanders said. “At last count, he had received funding from at least 60 billionaires. Our campaign has received more campaign contributions from more Americans, averaging $18.50, than any campaign in the history of our country.”