WASHINGTON -- New York City Mayor Bill de Blasio on Wednesday said likely presidential contender Hillary Clinton or whoever becomes the Democratic candidate in 2016 should run to the left by addressing income inequality to motivate the party's voters.

"I think there is a lot of room for a Democrat to speak to these issues," de Blasio said. "I think it could well be Secretary Clinton. But one way or another the Democrats have to speak to these issues."

De Blasio came to Washington to tout his progressive agenda and warn against repeating the mistakes Democrats made in losing so many seats in the recent midterm elections.

In an interview with Politico's Mike Allen here at a morning event, de Blasio spoke about Clinton, but also praised her potential rival on the left, Sen. Elizabeth Warren (D-Mass.), as an "indispensable" voice, and warned that Sen. Rand Paul (R-Ky.), a possible GOP presidential hopeful whose policies he rejects, has vote appeal because he comes off as "authentic."

The mayor also defended using the Rev. Al Sharpton as an adviser, agreed with the decision of his wife's chief of staff to go on leave and dismissed a poll suggesting New York voters' views on him are racially polarized.

And he said he hadn't smoked pot since college, and promised he would try to be a "better person" by arriving at events on time.

Pressed by Allen about whether Clinton would move to satisfy the party's liberal wing by taking on economic inequality, de Blasio said, "I'm hopeful. Look, I think she should. I think it's necessary."

De Blasio, who managed Clinton 2000 U.S. Senate campaign in New York, added, "I think a lot about her history and origins suggest it's natural for her."

He said that when he helped her unsuccessful presidential bid in Ohio in March 2008, he saw her speak to "core economic issues very powerfully."

But de Blasio said he is not an adviser to her, and he resisted talking about her as a candidate because she has not declared she's running.

Generically, he advised the Democratic candidate to "speak to income inequality" and "challenge the status quo" and "wealthy and powerful interests," while tying that message to a grassroots strategy.

He blamed Democrats' losses in the 2014 election on too many candidates moving to the middle and failing to inspire and motivate voters.

On New York issues, de Blasio stood by Sharpton as an adviser and friend when Allen asked about a poll showing a third of those surveyed said he relied on Sharpton too much.

He said he asks Sharpton for advice, but "that's it. I'll make my own choices."

De Blasio also defended Rachel Noerdlinger, his wife's chief of staff, calling her mistakes "minor."

He said he accepted her taking a leave of absence.

"She decided to tend to family matters and I think that was the right thing to do," he said.

In the afternoon, de Blasio talked about governing New York City at the Center for American Progress, which held a daylong conference for progressive Democrats.