Anthony Weiner for N.Y.C. mayor? Why he is no Mark Sanford.

Anthony Weiner is running for mayor of New York, less than two years after he resigned from Congress in disgrace over revelations about his extramarital, sexually explicit online exploits.

In a two-minute video released Wednesday morning announcing his mayoral candidacy, Mr. Weiner appears the quintessential family man. It starts with him and his wife, feeding their baby boy.  At the end, his wife – Huma Abedin, aide to Hillary Rodham Clinton – appears again, sitting next to Weiner on a New York stoop, endorsing his candidacy.

Weiner himself acknowledges he made some “big mistakes” and asks for a “second chance.”

“I’ve let a lot of people down,” Weiner says. “But I’ve also learned some tough lessons.”

Surely, he has also taken to heart the lesson of former Gov. Mark Sanford (R) of South Carolina, newly elected to his old congressional seat in a remarkable political comeback. In 2009, then-Governor Sanford went AWOL to visit his mistress in Argentina, after suggesting he was hiking the Appalachian Trail. He finished his term, but his wife divorced him.

In New York, there are plenty of reasons to take Weiner’s candidacy seriously. He has more than $4 million in a campaign war chest (though it was reportedly raised mostly before his resignation), and his wife has stuck by him. A Quinnipiac poll released Wednesday morning puts Weiner second in a crowded Democratic field, behind City Council Speaker Christine Quinn, 25 percent to 15 percent. He is a tireless campaigner, and while his brash style in Congress put some people off, it might be a fit for the Big Apple.

On Weiner’s campaign website, he lists “64 Ideas to Keep New York the Capital of the Middle Class.”

But Weiner is no Mark Sanford. Let us count the ways:

• Weiner is trying to come back much sooner than Sanford did, two years versus four years.

• Weiner is aiming for a more prestigious job – mayor of the biggest city in the United States, currently held by Michael Bloomberg. Sanford had the good fortune of seeing his old congressional seat open up, allowing him to show a little humility as he ran for a job less prestigious than the governorship.

• Sanford had less difficult competition than Weiner does – not that Sanford’s political resurrection was a sure thing. Plenty of voters in South Carolina’s First Congressional District weren’t ready to forgive and forget. He had to compete in a runoff for the Republican nomination. Then in the general, he faced a well-funded Elizabeth Colbert Busch, sister of satirist Stephen Colbert. Toward the end of the campaign, Sanford’s ex-wife accused him of trespassing on her property, and the National Republican Congressional Committee stopped investing in the race. But the district was heavily Republican, and Ms. Colbert Busch was a political novice. Sanford won by nine percentage points.

• Perhaps the biggest issue weighing against Weiner is the “ick” factor. The “weiner” jokes are back, as voters are treated to rehashes of Weiner’s lewd texts and tweets sent to women he had met online. Back in 2011, when confronted, Weiner lied about his actions before admitting to them.  

In the Quinnipiac poll, 49 percent of New York City voters don’t want Weiner to run, including 52 percent of women and 44 percent of Democrats. To avoid a runoff, the winner of the Democratic primary needs 40 percent of the vote.

But Ms. Quinn is a weak front-runner, and nobody is dismissing Weiner’s chances outright. Still, he has yet to attract top political talent. And even if he manages to win the Democratic nomination, he could encounter another hurdle on the route to City Hall: popular Police Commissioner Raymond Kelly, who may run as an independent.

The Quinnipiac poll showed 32 percent of voters would “definitely” or “probably” vote for Commissioner Kelly in the general if he runs. Among the other Democratic candidates, Public Advocate Bill de Blasio and former Comptroller William Thompson each polled at 10 percent among primary voters. Comptroller John Liu gets 6 percent and former council member Sal Albanese gets 2 percent. Twenty-seven percent are undecided.

The primary is scheduled for Sept. 10, and the general election is Nov. 5.