MADELEINE BRAND, host:

From NPR News, it's DAY TO DAY. In Connecticut, incumbent Democratic Senator Joe Lieberman is facing a surprisingly strong primary challenge. The one time presidential and vice presidential candidate is under attack by liberals for being too supportive of President Bush.

Yesterday in the Senate Lieberman voted against both Democratic proposals to set a timetable for withdrawing troops from Iraq. There's also speculation that Lieberman might leave his party and run as an independent. Slate magazine's John Dickerson has been reporting in Connecticut on the race. I spoke earlier with him about Lieberman's slowing Joe-mentum.

Mr. JOHN DICKERSON (Slate magazine): He's supported the Iraq war in his initial vote and then continuously he's supported it, and in doing so, they claim he's kind of thumbed his nose at progressives and people who have had legitimate criticisms and worries about Iraq. They think Senator Lieberman has kind of treated them dismissively. They feel misused by him, among other things.

BRAND: And who is his challenger, Ned Lamont?

Mr. DICKERSON: Ned Lamont is a cable company executive. He started a company that provides learning for colleges, and he's wealthy. He lives in Greenwich. And he is a progressive candidate who is mostly running on an anti-war platform. He gives speeches that include lots of talk about education and energy policy and pork barrel spending and so forth. But the real animating energies in this race are the dislike of Lieberman and also the dislike of the war, animating to the extent that Lamont has had this surge lately.

BRAND: Well, how serious is he a threat to Lieberman?

Mr. DICKERSON: Well, he seems to be an increasing threat. It's hard to figure out exactly how serious a threat. We're talking about the Democratic primary here. That's a small number of voters. The activists in the party tend to participate in those primaries more than your sort of middle of the road Democratic voter.

Those activists don't like Lieberman and they like Lamont. And Lamont's been coming up in the polls. He still trails by double digits, but he's been moving up in the polls, and there's a lot of indication that Lieberman and his group are worried that Lamont's doing too well in the Democratic primary race.

BRAND: And what are the chances then that Lieberman would flee the party and run as an independent?

Mr. DICKERSON: Well, it's hard to tell. The reason Lieberman would want to flee the party and run as an independent is he does quite well as an independent. He would, according to recent polls, beat Lamont rather handily if he ran as an independent. He polls well among moderate Republicans and unaffiliated voters. But he's got to decide and he hasn't done that yet.

He's had conversations with advisers about whether to leave or stay, but he's being coy publicly. And he says he won't rule it out, which is a little bit code. And he's in a position where he hasn't really come down firmly on whether he will, if he loses in the Democratic primary, bow out of the general election. The betting is essentially if he does lose in that primary then he'll run as an independent.

BRAND: In general though, how is Lieberman perceived in Connecticut? Is he liked?

Mr. DICKERSON: In general, Joe Lieberman is still well liked in Connecticut. The most reliable poll shows that even among Democrats they still want him to be re-elected. So he's favorable, he's got good favorability ratings, and people like his underlying sort of core behavior. So in this general election pool he still does pretty well.

BRAND: Opinion and analysis from John Dickerson. He's chief political correspondent for the online magazine Slate. Thank you, John.

Mr. DICKERSON: Thank you.

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BRAND: DAY TO DAY returns in a Joe-ment. Transcript provided by NPR, Copyright NPR.