Every four years, one side frets that a contentious primary fight is going to do lasting damage to the party's ultimate nominee. Most times, however, the scars are superficial. Rivals kiss and make up. And the attacks lobbed during the primaries are all but forgotten a few months later.

This year, however, Republicans' fears of a damaged nominee look more warranted than ever.

ABC/Washington Post polling taken last week (January 18-22) showed Newt Gingrich and Mitt Romney with sky-high negatives and low favorable ratings.

Thirty-one  percent of Americans had a favorable opinion of Mitt Romney, while 49 percent had an unfavorable opinion of him. The numbers were equally negative  for Gingrich: 29 percent viewed him favorably, while 51 percent viewed  the former House speaker unfavorably.

And  this was before the two really started to tear into each other this weekend.

Now, compare this with where other nonincumbent candidates were at this point in past campaigns, and the Romney/Gingrich numbers look even worse.

Favorable/ Unfavorable

Barack Obama (1/12/08): 65/30

John McCain (1/12/08): 61/31

John Kerry (3/7/04): 54/26

G.W. Bush (2/27/00): 49/39

Al Gore (2/27/00): 50/40

To be sure, we live in a fast-paced, ADD culture, where most of us can't even remember what we ate for dinner last night, let alone what candidates were fighting about months back. But, at some point, impressions start to form of these candidates. And those impressions are tough to change.