Vermont Senator Bernie Sanders endorsed New York City Mayor Bill de Blasio at a campaign rally at Terminal 5 Monday evening. De Blasio, who endorsed Hillary Clinton in the 2016 Democratic primary, is up for mayoral reelection Tuesday.

The venue was filled with impassioned supporters and hecklers alike. De Blasio and Sanders talked about pre-K as well as progressive economic values, and a plan for homelessness.

“I wanna tell you what this election here in New York is about,” said Sanders. “[It] is the understanding that everything that Mayor de Blasio is trying to do is exactly the opposite of what Donald Trump is trying to do.”

De Blasio may be seeking a local office, but Trump’s presidency was the rally’s focus.

“The best reason to vote on Tuesday, November 7th, is because of what happened last Tuesday, November 8th,” said de Blasio.

Although de Blasio endorsed Sanders rival Hillary Clinton to be the Democratic party’s presidential candidate, Sanders was an enthusiastic presence at the Terminal 5 rally who seemed to put the bitter nomination battle behind him. And while the incumbent mayor has been dogged by a festering homeless epidemic, soaring housing costs, and accusations of embracing a “pay to play” culture during his first term, the 76 year old Sanders appeared to have few qualms supporting de Blasio’s re-election.

With a large group of supporters dressed in red campaign shirts standing behind him on a stage displaying a large sign reading “This Is Your City,” de Blasio vowed to “stand up every day” to Trump. He promised to fight against White House initiatives to cut taxes for the wealthy, repealing the Affordable Care Act, or instituting a ban on Muslim visitors to the U.S.

De Blasio benefits from a New York constituency that loves anything anti-Trump. During the rally, he also drew loud applause when listing his accomplishments as mayor; like making pre-kindergarten education universal and free, and reducing stop-and-frisk by 93%. The 56 year old mayor asserted that New York is now the safest big city in America, adding that all New York City police officers will be required to wear body cameras going forward.

But Senator Sanders was the star of the night. He spoke passionately about the “disgrace” of childhood poverty and high childcare costs, saying they cripple middle-class working mothers and fathers.

“I want to congratulate the mayor and the first lady of this city for dealing with an issue that gets very, very little attention — that is the crisis of early childhood education,” said Sanders.

“Mom, single mom, mom and dad want to know that when they’re out working that their kid has quality childcare,” said Sanders, explaining that the days of dad going to work and mom staying home with the kids are long gone.

Sanders also supported de Blasio’s effort to repair the subway system and cut the cost of subway tickets in half.

The Democratic Senator was especially enthusiastic about the plan to impose a so-called millionaire’s tax to help pay for the subway maintenance.

”What makes senses to me, and his idea to pay for it, in a time of massive income and wealth inequality, is to tell the 1% they’re gonna have to pay a little bit more in taxes.”

“A lot more!” shouted a man near this reporter in the audience, without missing a beat.

Still, despite the support of one of the most popular politicians in America, and being projected to win in a landslide victory in the election next week, de Blasio has a long list of political enemies and outspoken critics.

Independent candidate for mayor, Bo Dietl, a former police detective, has been de Blasio’s loudest, and often times bombastic, opponent. During televised debates, Dietl has made a name for himself hurling raucous accusations at the mayor like, “I know a criminal when I see one. Mr. Mayor, you’re a criminal with your corruption and your pay-to-play.”

Dietl is not the only one who considers de Blasio’s transparency and political integrity to be dubious. A federal and state investigation into whether the mayor had been doing favors for wealthy donors last year was ultimately in March with no charges pressed.

Still, Sanders, one of the most outspoken politicians against pay-to-play culture, is endorsing the Democratic incumbent who is pushing a progressive agenda in one of the biggest cities in the country.

“On election day, let’s show the country, that by a large vote — if you like, a huge vote — let’s re-elect Bill de Blasio. Let’s show the world what this great city can do.”