The Republicans certainly criticized Clark's Kosovo strategy. Bill Maher had some line about how cowards bomb civilians from cruising altitudes (in reference to Kosovo and Serbia). And I've noted that Dennis Kucinich's supporters, in particular, aren't fond of Clark for these reasons. (D.K.'s supporters have done plenty of homework on Clark, it seems.)
I'm sure the GOP will dredge up all the muck they can find, and there will be some. That's always a question for a potential candidate and his/her family: do you want to go through that rough and tumble? (Ask Dan Quayle, Gary Hart, Ed Muskie, Kitty Dukakis, Bill Clinton, Al Gore, Geraldine Ferraro, and many others.) It's hard to imagine unless you've gone through some of it previously. I don't think there's really any race that fully prepares you for the presidential scrutiny, but I would argue it does help to have some electoral experience.
DailyKos has some interesting New Hampshire polling data on Clark. There are some problems with the poll, particularly that the first question lumped in "leaners" and the second didn't, so it's hard to compare them. The first question had Clark out, and Dean was 38, Kerry 26. (Pretty much in line with the prior poll, although we all knew +21 points for Dean was goofy, and Kerry did have a media blitz for his reannouncement.) Putting Clark in, and taking out the "leaners," has Dean at 31, Kerry at 20, Clark at 5. In other words, not much impact -- the bigger impact was from taking out the "leaners," and, not surprisingly that occurred in approximately equal proportions to each candidates' support in the first question.(*)
Kos goes on to point out that it's impossible to know what concentrated media exposure will do to Clark's 5 percent. (And what will that media exposure be? Positive? Critical?) However, it's important to note that, before any Clark announcement, we really do have solid Democratic candidates with lots of firm support in New Hampshire. (Dean is well outpolling "Don't know" any way you slice the numbers, for example.) It's not as if half the electorate is saying, "Well, damn, we're really missing (Candidate X) in this race."
I'd also go on to say that the first poll question didn't name Clark, but some people might have answered "Other" or "Don't Know" nonetheless to indicate support for him in the first poll. My point being that Clark's 5 percent in the second question may not have been entirely at the expense of other candidates from the first question, and that the "leaner" effect could have been yet greater.
For the record, I welcome Clark's candidacy or non-candidacy, whichever he chooses. I think it's great that the Democratic nominating process is so open and inclusive. I also think he'd make a terrific nominee, as would the vast majority of the other Democrats running.
(*)Yes, I know, a six point drop from 26 is a greater percentage drop than a 7 point drop from 38. So one could argue that Dean's support in this poll is firmer. But that's all well within the margin of error, so let's not get silly.