Primary conflict in N.Y.

Just when you thought the tension between the Clintons and Obamas was over, it has been revived.

Former President Clinton will headline a fundraiser later this month for Rep. Carolyn Maloney (D-N.Y.), a nine-term lawmaker who is about to formally declare a Senate bid against Sen. Kirsten GillibrandKirsten GillibrandOvernight Defense: VA chief 'deeply' regrets Disney remark; Senate fight brews over Gitmo Dems discuss dropping Wasserman Schultz Defense bill renews fight over military sexual assault MORE (D-N.Y.).

President Obama and Sen. Charles SchumerCharles SchumerPuerto Rico debt relief faces serious challenges in Senate Overnight Healthcare: House, Senate on collision course over Zika funding Ryan goes all-in on Puerto Rico MORE (D-N.Y.) are strong supporters of Gillibrand and are committed to campaigning actively for her next year.

White House Chief of Staff Rahm Emanuel warned Rep. Steve Israel (D-N.Y.) this spring of how engaged Obama would be in the primary, which prompted Israel to reconsider a bid for the upper chamber.

Rep. Carolyn McCarthyCarolyn McCarthyLobbying world House Dem says leaders must know when to move on Franchise owners flock to DC in defense of McDonald’s MORE (D-N.Y.) was also mulling a bid, but decided against it, although neither she nor Israel has ruled out endorsing Maloney.

Matt McKenna, Clinton’s spokesman, recently told The New York Times that the ex-president “agreed to do [the fundraiser] some time ago as a way to say thank you to Congresswoman Maloney.”

Maloney backed Hillary Rodham Clinton when she was New York’s junior senator and was making a bid for the White House. So did every member of Congress from New York.

Bill ClintonBill ClintonWATCH LIVE: Bill Clinton speaks at NJ rally The Hill's 12:30 Report The Trail 2016: Interleague play MORE knows that helping Maloney causes eyebrows to be raised. Certainly, there are some puzzled people over at 1600 Pennsylvania Ave. wondering about Clinton’s move.

Ways and Means Committee Chairman Charles Rangel (D), the dean of the New York delegation, has wondered aloud why Obama got so involved in the contest over Clinton’s old seat.

Earlier this year, the White House was concerned it could lose the seat to former New York Gov. George Pataki (R) or Rep. Pete King (R-N.Y.). The thinking was that a bruising Democratic primary could allow Pataki or King to win next fall. But Pataki and King are showing less, not more, inclination to get into the race.

Politics is difficult to predict, but it is a safe bet that Democrats will keep New York in their column, whether the winner is Gillibrand or Maloney.

Some media accounts have portrayed Maloney’s bid as an uphill and lonely quest against the White House. Don’t believe it.

Maloney is a shrewd legislator who just helped pass credit card reform. She knows how to read polls and is well-aware that she can portray Gillibrand as both a conservative Democrat and a flip-flopper.

Gillibrand has deftly moved left since being appointed to the Senate, most notably on gun control. But changing positions is always tricky.

Still, Gillibrand has a popular president behind her, and perhaps more importantly, she has Schumer on her side. Schumer has a vast political operation throughout every county in New York. He usually gets what he wants, and he will go all out to get Gillibrand reelected.

Whoever wins, Gillibrand-Maloney will be one of the most fascinating races of the 2010 cycle.