Several unfamiliar faces knocked on doors in Marlboro Houses in Brooklyn on Monday.

Max Rose is running for the 11th congressional district, which covers Staten Island and a portion of Brooklyn, trying to take down Republican incumbent Dan Donovan.

On Monday, he brought reinforcements from almost 700 miles away, from one lead crisis to another.

Dan Kildee, the Democratic congressman from Flint, Michigan was trying to sell a candidate to the people of Brooklyn.

"You come to a place like this, you see that, clearly, we have to do something to improve housing," Kildee said. "He gets it, and if we work to solve this problem, we are also going to work to solve problems in places like Flint."

It's certainly a sign that Rose has the big time backing of national Democrats, who are betting they can flip the seat from red to blue.

Clearly, the GOP congressman was unimpressed:

"That is just a reflection of Nancy Pelosi and her team coming out and trying to influence the voters of our community, which the voters are not going to allow happen," Donovan said. "He's a product, hand-picked by them, to come into New York and try to influence them with their liberal ways, and New Yorkers are too smart for that."

"Dan Donovan has a Nancy Pelosi obsession. Every time you talk to him, he loves talking about Nancy Pelosi," Rose said. "I've been very clear: I am not supporting Nancy Pelosi as the leader. I'm not, and I will not."

The last time this seat was in Democratic hands was in 2008, during that national "Blue Wave."

On cue, President Barack Obama endorsed Rose on Monday, along with dozens of other Democratic candidates.

When NY1 caught up with Donovan minutes after the announcement, he touted his own support. "He can have Obama's endorsement; I will take the transit union," the congressman said.

Donovan does not have to return to Washington D.C. for votes until after Election Day, meaning he and Rose will continue to clash on the campaign trail full-time for the next five weeks.