Sen. Joe Lieberman's (I-Conn.) favorable ratings have taken almost a 10-point drop in the past two weeks, a new poll found.

31 percent of people told a CNN poll conducted Dec. 16-20 that they had a favorable opinion of Lieberman, a key Senate centrist who'd opposed healthcare reform only until recently. Opinion toward Lieberman, though, was down from a 40 percent favorable rating in the same CNN poll conducted December 2-3 of this year.


Poll respondents' unfavorable opinion of Lieberman ticked upward over the same period. 34 percent of those polled said they now have an unfavorable opinion of Lieberman, compared to 28 percent who have an unfavorable opinion.

It is difficult to pinpoint when or why Lieberman has taken a hit: In the past two weeks, he not only crucial in helping remove the healthcare bill's public option and Medicare buy-in provisions, but also subsequently announced that he would join with Democrats to support the bill after those provisions were removed.

Still, many liberal bloggers and activists have griped about unseating Lieberman, who lost a 2006 Democratic primary to Ned Lamont, only to win reelection as an independent (who still caucuses with Democrats in the Senate). Lieberman's recalcitrance over healthcare and his having supported Sen. John McCain's (R-Ariz.) presidential campaign have also stoked ire from the left toward Lieberman since that 2006 primary.

Over that same period, conservatives have at times lionized Lieberman for his willingness to break with Democrats and block or force changes to key pieces of legislation.

Roughly the same number of those polled said they had never heard of Lieberman, the 2000 Democratic vice presidential nominee, in both polls. The percentage of those who had no opinion of the Connecticut senator remained unchanged.

The poll, conducted by Opinion Research from December 16-20, has a 3.5 percent margin of error.