Giuliani's greatest decline, as noted, has been among people who are following the race very closely, people perhaps more likely to be tuned in to recent questions about matters such as police security for his then-girlfriend when he was New York City mayor, and the identity of his security consulting firm's business clients.
Huckabee, governor of Arkansas and a Baptist minister, first caught on in Iowa, where an ABC/Post poll just before Thanksgiving found him challenging Romney, who's focused heavily on the state. Huckabee subsequently advanced in national polls, albeit not in New Hampshire, where he had just 9 percent support in an ABC/Post poll last week.
Huckabee's support in this national poll is up by 10 points among likely voters from last month. As in Iowa, he's advanced particularly among evangelical white Protestants, jumped from 13 percent support last month to a field-leading 29 percent support now. The main loss among evangelicals was McCain's, from 23 percent down to 12 percent.
It matters: Evangelicals account for 31 percent of all Republicans and Republican leaners, and 37 percent of likely Republican primary voters.
RELIGION: Romney, for his part, has gained seven points overall among registered voters, though less (a slight four points) among likely voters. Better is his progress on the issue of his religion, which he addressed in a speech last week: While 21 percent of leaned Republicans say they're less likely to vote for someone who's a Mormon, that's down from 30 percent in June and 36 percent a year ago.
These judgments matter; Romney has 20 percent support from Republicans who say Mormonism makes no difference in their choice, running second to Giuliani in this group versus almost no support among those less apt to back a Mormon candidate.
By contrast, this poll finds no net negative effect of a candidate's being a woman, an African-American, or a minister or other religious leader.
Romney may face further questions about his religion. Most Americans, 57 percent, believe they don't have a "good basic understanding" of it. And just 42 percent view Mormonism favorably overall; about as many, 39 percent, see it unfavorably, while 19 percent have no opinion. Romney's support is far higher, 28 percent versus 6 percent, among people who have a favorable opinion of his religion.
Religion is likely to continue to play a fascinating role in the race. Among all Americans just 27 percent say a political leader should rely on his or her religious beliefs in making policy decisions, a new low in ABC/Post polling and potentially a challenge for Huckabee or Romney in a general election contest.
At the same time, in his race for the nomination, Huckabee has 21 percent support among leaned Republicans who say a candidate should rely on his religious beliefs in making policy decisions. Among those who oppose reliance on religious belief in policy matters, Huckabee's support drops to 10 percent.
GOP ATTRIBUTES/ISSUES: Giuliani, whatever his problems, continues to prevail on two important attributes: He's easily seen as the most electable in November (with nearly a 3-1 lead over Romney, the No. 2 finisher on this attribute), and as the strongest leader (2-1 over McCain). Giuliani also has a scant five-point edge over McCain and Huckabee as the candidate who "best understands the problems of people like you."