Gov. Andrew M. Cuomo stumped in the Bronx Sunday, seeking to drum up support for running mate Kathy Hochul, while attacking the experience of his Democratic rivals in Tuesday's primary.

Cuomo has largely avoided the campaign trail and is leading in polls. He faces a challenge from Fordham University law professor Zephyr Teachout. He told a crowd of more than 150 supporters gathered at a rally in Riverdale that "experience matters" when it comes to making a choice for the top of the Democratic ticket.

Hochul, a former member of the House and a former Erie County clerk, is running against Tim Wu, a Columbia University law professor who has never held office.

"People say, 'Well, I don't have any experience. Well, I can be lieutenant governor,' " Cuomo told those attending the rally for Sen. Jeff Klein (D-Bronx), who faces a primary challenge from former city councilman Oliver Koppell.

"Well, I don't have any experience, but I think I can be a heart surgeon. Anyone here want to be my first patient?" Cuomo said, never mentioning Teachout or Wu by name. "I don't want anyone experimenting with the lieutenant governorship of the state of New York."

When asked about Cuomo's comments at a news conference in midtown Manhattan Sunday, Wu said, "I'd love to have a conversation about qualifications," and said Hochul's most recent job was government relations specialist for Buffalo-based M&T Bank.

"I've worked at the Supreme Court, for the Obama administration in consumer protection, and I was a director at a telecommunications firm in Silicon Valley," Wu said. "If the governor thinks the best qualification for lieutenant governor is being a bank lobbyist, well, that says something about his core values."

Teachout and Wu have been aggressively campaigning against Cuomo and Hochul, criticizing the duo for not being "progressive" enough.

Both organized a "walking tour" for reporters Sunday of the homes and offices of some of Cuomo's biggest campaign donors, while calling for campaign finance reforms.

"The power to speak has been concentrated in too few hands," Teachout said. "Cuomo supports entrenched private interests."

Hochul told the Bronx crowd she would put her "heart and soul" into helping enact the state's version of the Dream Act -- a measure that would provide in-state tuition rates and scholarships to immigrants who entered the country illegally who seek financial aid for college.

"If there's anybody in the state of New York who does not support the Dream Act, I'm going to put them in a room and sit them with these young people," Hochul said. "If you come away from it, after listening to them, feeling like you still don't want to pass the Dream Act, then you do not have a heart."

Wu has previously criticized Hochul's opposition to providing driver's licenses for immigrants living in the country illegally when she served as county clerk.

The rally came hours after Mike Long, chairman of the state Conservative Party, sent out an email telling "conservative Democrats" to support Teachout.

"Ms. Teachout and the Party do not agree on philosophical and fiscal issues, but at least she is not part of the old boy network and culture of corruption that is killing our state," Long wrote.

Asked about the email by reporters, Cuomo brushed it off as a "Republican tactic."