NEW YORK — Bernie SandersBernie SandersThe Hill's Morning Report - Crunch time arrives for 2020 Dems with debates on deck The Memo: All eyes on faltering Biden ahead of first debate Progressive group launches campaign to identify voters who switch to Warren MORE rallied a huge crowd in his home borough of Brooklyn on Sunday afternoon with a speech that drew stark and sometimes scathing comparisons with his rival, Democratic presidential front-runner Hillary ClintonHillary Diane Rodham ClintonThe Hill's Morning Report - Crunch time arrives for 2020 Dems with debates on deck The Memo: All eyes on faltering Biden ahead of first debate Trump says he's not prepared to lose in 2020 MORE.

Sanders, who has become more sarcastic about Clinton of late — including in the ninth and fieriest debate between the two last Thursday — mocked the former secretary of State for her refusal to release the transcript of her paid speeches to corporations, including Goldman Sachs.

Noting that Clinton has received as much as $225,000 per speech, Sanders said: “Now, if you give a speech for $225,000, it must be a pretty damn good speech, must be a brilliant and insightful speech analyzing all of the world’s problems, must be a speech written in Shakespearean prose. And that is why I believe Secretary Clinton should share that speech with all of us.”

Sanders devoted a significant portion of his hour-long address in Prospect Park to assailing Clinton for issue after issue on which he suggested she was insufficiently liberal or flat-out wrong: free-trade agreements; fracking; the war in Iraq; her refusal to call for a $15 per hour minimum wage; and her reluctance to support raising the income cap on Social Security contributions. 

“I have challenged Secretary Clinton, and challenged her and challenged her — and she still refuses to come on board” on Social Security, Sanders said.

More generally, he framed the support for his candidacy as a consequence of people being “sick and tired of establishment politics and establishment economics.”

There is nothing new about Sanders highlighting contrasts with Clinton. But the withering tone he is adopting will worry those in the Democratic Party who see the former secretary of State as the all-but-inevitable nominee. There are already murmurs that such attacks wound her and make it more difficult to unify the party for November’s general election.

But the Vermont senator is pulling no punches in a bid to pull an upset win in New York’s primary, which takes place on Tuesday.

Sanders needs to spring a major surprise here if he is to retain a plausible path to the Democratic nomination. Clinton leads him by around 250 pledged delegates — won via the results of primaries and caucuses — and has an even more commanding advantage among superdelegates.

She also leads Sanders by 12.5 points in the Empire State, according to the RealClearPolitics polling average.

Sanders, his Brooklyn accent undiminished by his four decades in Vermont, stressed his connection to the borough on Sunday, mistily recalling being “a kid growing up in Flatbush” who could never have imagined addressing a crowd like the one before him, which he estimated at 20,000. He was introduced on stage by actor Danny DeVito, who referred to Sanders as “a hometown boy.”

The rally, held amid blissful weather conditions in Prospect Park, was more reminiscent of a rock concert than a conventional political rally in many respects: the youthful crowd, the musical warm-up acts ranging through reggae, hip-hop and indie rock — and even the occasional waft of herbal scents through the crowd. 

Homemade signs attested to the love for the 74-year-old senator — and skepticism of Clinton. “Bernie is bae,” read one. “Hillary is for herself, Bernie for us,” said another.

Among the attendees was Athena Soules, a Brooklynite and creative activist who had made a large “Bernie” banner for the occasion.

The first time she had become aware of Sanders, “I got that he was an authentic man of the people,” she said. “Imagine someone like that in the White House? I don’t want anything more than that.”

Of Clinton, Soules said with distaste, “She’s right up there with Wall Street. She is both the government and the corporations.”

Earlier Sunday, Sanders toured public housing in Brownsville, one of Brooklyn’s most marginalized neighborhoods, and attended a church service in Harlem.

On the night of the New York primary, however, Sanders will be in Pennsylvania. The Keystone State holds its Democratic contest on April 26, but the decision to leave New York on primary night may suggest the Sanders campaign is not quite so bullish as it claims about pulling an Empire State upset.