Sen. John Edwards knows that Sen. Hillary Clinton's biggest vulnerability among Democrats is the perception that she is not electable. A polling memo prepared for internal campaign consumption but obtained by this semi-checked out column shows the reasons why.

Pollster Harrison Hickman summarizes the national numbers:

Nationwide general election polling shows John Edwards is the Democrat with the best chance of defeating the Republican candidate in the 2008 general election for President. Edwards is the only Democrat with a significant lead in a head-to-head match-up against Republican frontrunner Giuliani.

Against the other three major Republican candidates, Edwards’ average margin of victory is virtually identical to that of Barack Obama, and significantly higher than Hillary Clinton’s average margin. Edwards also outperforms the other Democratic candidates in match-ups with Republican candidates in key battleground states including Iowa, Wisconsin, and Ohio. Further, unlike other Democrats who must “run the table” in states where Democrats have been competitive in recent elections, Edwards brings new states into play. This provides alternate scenarios – and a margin for error – when it comes to amassing 270 electoral votes.

The buried news here is that Barack Obama does almost as well -- except against Giuliani, where Edwards does a little better. Edwards is smart to make an argument out of the Electoral College map: Giuliani puts New Jersey and Pennsylvania into play almost instantly, and the Democrats will need to find ways to force Republicans to spend money in previously red states... Virginia among them.

In looking at the overall win-loss-tie records, Edwards again stands out with easily the best total
record.

At least one poll in the last two and a half months shows Clinton losing to every Republican
challenger, even Romney and Thompson, who neither defeat nor tie either Obama or Edwards,
confirming Clinton as the weakest major Democrat in the general election.

Edwards’ status as the best Democrat against frontrunner Giuliani is again confirmed by this
measure, as he suffers no losses, while both Clinton and Obama struggle to win more than they
lose in that matchup.

I've written about this elsewhere; I think the case is less cut-and-dried than Edwards makes it out to be, but it's not my case to make -- it's Clinton's.