New York Attorney General Eliot Spitzer, who made some powerful enemies with his crackdown on Wall Street abuses and is now running for governor, could face a strong challenge from a fellow Democrat bankrolled by one of Spitzer's fiercest corporate foes.

Spitzer has at least $12 million in his ever-growing war chest, national stature from his attacks on corporate wrongdoing and a commanding lead in the polls. But that may not stop Tom Suozzi, a brash Long Island politician, from getting into the race.

Suozzi, the Nassau County executive, has the hugely influential backing of Home Depot founder Ken Langone, a Long Island billionaire who has tangled with Spitzer on Wall Street and has vowed to raise "as much money as I can" to help knock off the two-term attorney general.

Suozzi has yet to declare his candidacy officially but filed papers Wednesday to form a fundraising committee for a gubernatorial run, a state elections official said.

If he does run, he will have to upset a better-known candidate who already has the blessing of many Democratic party elders thirsting for victory after 12 years of Republican Gov. George Pataki.

Langone was sued by Spitzer over the compensation controversy involving former New York Stock Exchange chairman Richard A. Grasso. Langone formerly served on the board of directors of the NYSE. Spitzer's lawsuit is challenging the $187.5 million severance package that Grasso got when he quit as chairman in 2003.

"I will leave no stone unturned to help Tom Suozzi wage a very successful and effective campaign," Langone told The Associated Press this week. He added that Suozzi has done a marvelous job as county executive and is "focused like I've never seen a politician in my life."

Spitzer spokesman Ryan Toohey did not mention Suozzi when asked about the potential challenge.

The attorney general is "excited about a campaign where he can talk to New Yorkers about his record as a reformer and his vision for making state government address New York's critical needs, like health care, education, property taxes and new jobs," he said.

A Quinnipiac poll last month showed Spitzer holding a 69-11 lead over his potential challenger.

"Spitzer has a five-lap lead, sure," said Maurice Carroll, director of the Quinnipiac University Polling Institute. "But it's only January. ... The guy (Suozzi) is real." He added that there is still time for the Wall Street money to "win some name recognition." The primary is not until September.

Taking on the party establishment is not a new role for Suozzi, a 43-year-old lawyer and accountant.

First elected mayor of suburban Glen Cove at 31, he established himself as a maverick by defeating his party's choice for county executive in a 2001 primary. In 2004, he created the FixAlbany campaign, exposing what he called a dysfunctional state legislature. That effort led to the defeat of a state assemblyman from Long Island.

The tactic so outraged the state Democratic leadership that he was left off the roster of delegates at his party's national convention. He went to Boston anyway with credentials provided by John Kerry's presidential campaign.

Suozzi coasted to a landslide re-election victory in November, boasting of having cured the fiscal health of Nassau County, where voters for decades elected no one but Republicans.

He brushes aside talk of a run for governor, saying, "I'm very flattered by the increasing speculation and interest."

In the same conversation, however, he outlined four key issues he predicted will be important for "whoever runs for governor": high property taxes; low-performing schools; the underperforming upstate economy; and affordable housing in the New York City area.

Spitzer himself is no stranger to fighting the establishment. He has gone after mutual funds, insurance companies, the NYSE and banks in his long-running effort to root out corruption on Wall Street.

But he has drawn the scorn of some executives who believe he is anti-business and is using his headline-grabbing investigations to advance his gubernatorial campaign.

Suozzi, who has about $4 million in his campaign war chest, will need to be careful he is not perceived as a lackey for Langone, political observers said.

"It's a double-edged sword," said Democratic strategist Hank Sheinkopf, who has worked for Spitzer in the past. "He helps raise money, but it potentially hurts because it gives Spitzer an argument against Suozzi."

Suozzi is slowly starting to attract some attention. Conservative TV commentator John McLaughlin raised eyebrows this month from his panel of political pundits when he tapped the Long Island Democrat as "destined for political stardom."

"With Suozzi in the race, all bets are off," McLaughlin bellowed.