"Now for the first time, her low likeability levels are costing her votes, as Democratic-party voters are abandoning her to support Barack Obama," Morris said. "She is losing her base."

National polls are suspect at this stage of the election cycle, which is really all about the candidates' respective strength in the key primaries and caucus states, especially among key demographic subgroups that make up the base of their support.

In Clinton's case, however, Gallup found she had lost 7 percent of her favorability among women in general, 10 percent among younger women aged 18 to 49 and 11 percent among unmarried women.

Zogby underscores the central thrust of Gallup's findings. Democrats appeared to be moving away from Clinton and toward her two chief rivals, Obama and former North Carolina senator John Edwards, he said.

Notably, Edwards, who has 16 percent support in the national Gallup poll, was still running in first place in the latest Iowa caucus polls with 30.3 percent, followed by Clinton with 26.8 percent and Obama with 19.5 percent.

Zogby's other state-by-state polls further confirm that Clinton's numbers are nothing to write home about.

"When you look at Hillary's numbers in the state polls, and the fact that she has 100 percent name recognition among voters, the fact that she's polling in the 20s and low 30s is not good," he said.

Clinton's organization has the best political strategists money can buy, led by the craftiest Democratic campaign Zen master on the planet, her husband Bill Clinton, who plays a central role in every decision she makes. But it's not too premature to say at this point that Clinton's campaign is in trouble.