By a lopsided 76-15 percentage points, Democrats in The Hill’s Air War survey (Page 20) think Democrat Ned Lamont’s campaign ads are more effective than those of the incumbent he is challenging in the Connecticut Democratic primary, Sen. Joe Lieberman.

The Lamont ads show Lieberman’s lawn signs being barked at by a dog, pulled up by homeowners and dumped in the trash. In contrast to this aggressive stuff, Lieberman’s ads are mild recapitulations of his record. Dignity and effectiveness don’t necessarily go hand in hand.

The theme of Lamont’s ads is rejection — Democrats turning away from their favorite son. This probably hits a nerve because the favorite son says he is willing to turn away from his party. Lieberman has declared that if he is dumped by the left-wingers who dominate primary voting — the extremes carry disproportionate weight in primaries everywhere — he will run as an independent.

Lieberman says Connecticut voters should have the chance to decide to keep their senator or trade him in. And he is surely right that voters in the general election will be keener on him than are the party activists.

But by telling his party that he’ll reject its decision if he doesn’t like it, Lieberman invites a reciprocal response — you won’t respect us, so we won’t choose you — and makes primary defeat that much more likely. True, he was backed into a corner by questions about what he’d do in the event of primary defeat — perhaps he had to answer — but answering effectively that he can do without the party was not deft.

Does that mean he is doomed? You might think so, but not necessarily. Lieberman won 63 percent of the vote in 2000 and, in theory, he and Lamont could split the state’s Democratic vote, allowing the Republican candidate to sneak through. But the GOP’s Senate nominee, Alan Schlesinger, is mired in questions about his gambling habits. It’s being suggested that pressure will mount for him to pull out. Either way, he is not looking like a potent force.

Whatever Lieberman’s campaign missteps and whatever his chances of losing the party primary next month, it would be a brave bookie who would give you long odds against the incumbent senator from Connecticut returning next year to start another six years on Capitol Hill.