Endorsements aside, of course the real strength of the Clinton primary campaign is this data pointed to by Todd Beeton:
For example, according to The National Journal's composite senate rankings for 2006, Hillary Clinton is the least liberal of the Democratic senators running, getting a liberal score of 70.2 vs. Biden's 77.5, Dodd's 84 and Obama's 86 (the 10th most liberal score.) But in a new Rasmussen Poll out today, more Democrats see Clinton as "liberal" (33%) than either Obama (31%) or Edwards (21%.) And while a solid 58% of Democrats identifies Clinton as moderate or conservative, a whopping 66% think John Edwards, the candidate running the most progressive campaign, is either moderate or conservative.
In part, you see here that identity trumps ideology even in people's assessments of ideology. John Edwards has the accent of a moderate-to-conservative Democrat, so he must be one. But this is also the fruit of the fact that for a number of years our popular culture essentially defined Hillary Clinton as identical to liberalism, especially in the non-political media where most Americans get their political information.
But of course what's an asset in a primary campaign in this regard is big trouble in a general election, and this has always been a wellspring of skepticism about her merits as a nominee to me. Why would you want your party's standard-bearer to be seen as much more liberal than she really is?