Rep. Steve Israel’s mission could not be more clear. But it’s one he says he may not achieve.

As the new chairman of the Democratic Congressional Campaign Committee, the Brooklyn-born New York Congressman must pick up 25 seats in the next election. Anything less means House Democrats will spend another two years fighting political irrelevance.

“I have one of the least complicated jobs in the House leadership. Winning districts. 25 seats,” Israel told Roll Call in an exclusive interview Friday. “I can guarantee you that the House will be in play this cycle. I can guarantee you that the Republicans are already nervous and will be more nervous as we get deeper into the cycle.”

Israel admitted he may fall short of that 25-seat goal: “But I will not, in the second month of the cycle, make an assessment of whether it will be 20, 25, 30 or 35.”

He continued: “And unlike my friend [National Republican Congressional Committee Chairman] Pete Sessions, who proclaimed that the Republicans will add seats in 2012, I don’t believe that bravado wins elections.”

There’s little doubt that Israel is a fighter who will push an aggressive agenda over the coming 21 months. But the six-term Representative and lifelong Mets fan is also a realist.

He filled the roles of attack dog, cheerleader and seasoned politician in the same Friday morning conversation, one moment lashing out at outside conservative groups as “American cowards” and the next vowing to defend Democrats who voted against his leadership team. The 52-year-old graying Congressman insisted that Nancy Pelosi won’t be a factor in 2012.

Of a list of 11 targeted Blue Dog Democrats the NRCC shared with Roll Call last week, seven voted against the California Democrat for Minority Leader. Israel promised to work as hard for those seven as he would anyone else “who will elect a Democrat as Speaker.”

“If in 2012 the central thematic is who leads the Democratic Caucus, then I will surrender my DCCC paycheck because I will have failed miserably,” Israel said he told the Blue Dogs during their New York City retreat last week. “2012 is going to be about the president of the United States and House Republicans. … The issue of who leads the Democratic Caucus is going to be absolutely irrelevant.”

Israel, who staunchly defended Pelosi last year when she came under fire from members of her own Caucus who blamed her for Democrats losing control of the House, described his relationship with the California Democrat as “excellent.”

He served as Northeast recruitment chairman during the 2008 cycle and said his efforts in special elections in the Empire State that cycle helped solidify his relationship with Pelosi.

“The DCCC and the Speaker asked me to just go into these districts, roll up my sleeves and help through the mechanics, and I’d like to think that that’s what developed the relationship and the confidence that she says she has in me,” he said.

This cycle, Israel is fighting to make Republicans — and their internal schisms — the focus of the national political narrative.

“The divisions aren’t on our side. The divisions are on the Republican side,” he said. “We’re not the ones who can’t get a bill passed on the floor of the House of Representatives this week. … We’re not the ones who just can’t find 218 votes for legislation. So to talk about divisions among Democrats, I think, is to ignore the more clear and powerful divisions that are paralyzing the Republicans.”

Democrats pounced last week on a series of GOP missteps.

In less than 24 hours, GOP leaders — faced with an insurrection within their own ranks — were forced to pull a trade bill from the calendar and failed to muster the two-thirds majority needed to pass one of Majority Leader Eric Cantor’s signature YouCut proposals, as well as an extension of the USA PATRIOT Act. And after the trio of legislative setbacks, conservatives forced GOP leaders to identify deeper spending cuts in the stopgap spending measure set to come to the floor this week.

Israel is already facing races, with special elections looming in California and New York after two unexpected vacancies. Rep. Jane Harman is leaving to take another job, and Democrats are expected to hold her Los Angeles-area seat. Republican Rep. Chris Lee abruptly resigned last week following the publication of a romantic e-mail exchange that the married former lawmaker allegedly had with a woman whom he contacted via Craigslist. Lee’s New York district is heavily Republican. If the DCCC flips the seat, it would be the ninth-most Republican district held by a Democrat. It will also be a target for redistricting since New York is losing two seats.

To compete there and in 2012, Israel must turn Republican missteps into political capital in districts across the nation. And to do that, he needs money.

The DCCC finished 2010 with debt exceeding $19 million and just $800,000 in the bank ­— that’s almost twice the debt of the NRCC and just a third of its cash on hand. Israel’s first expenditure as part of the “Drive to 25” campaign targeted vulnerable Republicans in 19 districts. But the effort, which included radio ads and e-mails, totaled just $10,000, or less than $600 per district.

The outside conservative group Crossroads GPS fired back soon after, spending $90,000 on “real buys” to defend the Republicans.

“I love adversaries who cut off their nose to spite their face. Crossroads never anticipated having to spend money in January and February. The more they teach me lessons by emptying out their bank account, the happier I’ll be,” Israel said, noting that the skirmish led to several press reports about Crossroads, which does not disclose its donors. “The more we get stories about Crossroads and American cowards ­— all these cowardly groups that are hiding under the robes of Supreme Court justices, the better it is for us.”

Israel would not share updated fundraising totals through the first month of the year, but he said heightened efforts to collect Members’ dues have been “very, very strong” in January. Coupled with
$1 million in December online donations ­— averaging $32 apiece — he said he was optimistic about the DCCC’s financial posture.

“So the despair on our finances in the hours after the election has been answered by new facts on the ground, and that includes our Member dues,” he said.

Going forward, the chairman is devoting much of his time to recruitment in an effort to push a full offensive in 2012, when Democrats should have plenty of opportunities, on paper at least. There are 61 Republicans serving in districts that Obama won in 2008 compared with 12 Democrats serving in districts won by  Sen. John McCain (R-Ariz.).

Israel spends three weekends a month on recruitment road trips and will travel to Florida next week, having already visited Arizona and Illinois, among other states.

He is also beginning to play some defense. The DCCC staff will name lawmakers to its Frontline program for vulnerable incumbents before the end of March, according to Israel. All but 10 of the DCCC’s 42 Frontline candidates in 2010 lost their seats.

Sitting at a small conference table inside his second-floor corner DCCC office Friday morning, the military history buff promised that he would fight aggressively to recapture the House majority in 2012, despite the admission that he may fail.

“Members know that we’re being aggressive,” he said, sipping from a Gettysburg coffee mug and glancing at a nearby painting of a colonel fighting in that pivotal Civil War battle. “They like seeing headlines that say, ‘Democrats’ newfound aggressiveness.’ They like turning on the television and hearing prominent pundits say, ‘The Democrats are fighting back, they have backbone.’ They are willing to fund an operational plan based on assertiveness. And they’re seeing that. They’re absolutely seeing that every day.”