In an effort to throw off her earnest image and display a hint of self-deprecating humor, Senator Clinton, a Democratic presidential candidate, has released a spoof of the ending of “The Sopranos” television series, which features her husband, President Clinton, for the first time in an online campaign commercial.

Set in a diner, like the unresolved final scene of the hit television series, Mrs. Clinton echoes Tony Soprano’s last actions as she leafs through the jukebox song list. Playing in the background is Journey’s “Don’t Stop Believin,'” the same song that the fictional mob boss picked from the jukebox in the show’s final scene.

As in David Chase’s cryptic denouement, a tall figure ambles into the diner. It is Mr. Clinton, who sits across from his wife as they peruse the menu. Mrs. Clinton orders a round of healthy carrot sticks as an appetizer. “No onion rings?” the food-loving former president asks, a reference to the Soprano family’s calorie-laden choice of starter.

In a further homage to the mafia soap, Vince Curatola, who played New York mob boss Johnny “Sack” Sacramoni, walks by the Clintons’ table, a snarl on his lips.

“Where’s Chelsea?” Mrs. Clinton asks. Just as in “The Sopranos,” where Meadow Soprano was delayed getting to the table because she has trouble parking her car, the screen cuts to a car tire scraping the curb. “Parallel parking,” Mr. Clinton responds.

“How’s the campaign going?” he asks.

Mrs. Clinton quotes Tony Soprano’s last words.

“Well, like you always say, focus on the good times.”

The clip then concentrates on the purpose of the parody: the announcement of the song that will become the theme of the Clinton campaign. “So what’s the winning song?” Mr. Clinton asks. “You’ll see,” comes the reply.

“My money is on Smash Mouth,” he says. “Everybody in America wants to know how it’s going to end.”

“Ready?” Mrs. Clinton asks and the scene fades to black.

Unlike the “Sopranos” ending, which caused such consternation and anger, visitors to the Clinton Web site are not left in the lurch. Instead, viewers are invited to listen to the winning song, Celine Dion’s “You and I,” and a single word invites supporters to “contribute.”

The scene, filmed in a diner in Mount Kisco, N.Y., near the Clinton home in Chappaqua, is the culmination of a month-long campaign to engage existing supporters and win over new ones. Running on the HillaryClinton.com Web site and on YouTube, the run-up to the announcement of the campaign song has been set out as a competition much like “American Idol.” And it has proved to be an enormous success, attracting more than a million hits.

It is a bold move by Mrs. Clinton, whose stern and serious campaign so far has been short on humor. And it is sure to attract attention from voters as well as from latenight chat show monologue writers.

Some political strategists may think that inviting comparisons between the Clintons and the most famous mafia family in America — a dysfunctional mob family who do not think twice about committing murder, theft, and adultery — may be offering an unnecessary hostage to fortune.