No speech sends more shivers up the spine of a presidential nominee than the second place finisher's moment on the convention dais. Ask George Bush Sr. how that whole Pat Buchanan "culture war" speech worked out for his re-election campaign or what Jimmy Carter thought about Ted Kennedy's "the dream will never die" speech, which mentioned the incumbent President once.
The specter of both these speeches and the political disunity they underscored hangs over the head of Barack Obama as Hillary Clinton prepares to deliver her speech tonight at the Democratic National Convention.

Now on one level, the speech tonight will be offered in a far different context than those of Buchanan and Kennedy. Both had significant ideological differences with their party standard bearer. The fissures that separate the Clinton and Obama camps are much more about personality than policy and thus, on the surface, more easily bridgeable.

But considering Obama's continued weakness among Hillary supporters, the stakes could not be higher (according to some polls, as many as 30 percent of Clinton voters may not support Obama).

Obama must find a way to appeal to the significant number of Clinton supporters who continue to maintain reservations about his candidacy. Indeed, bringing Democrats home may, in the end, be the key to Obama's victory in November. Her speech tonight will go a long way toward allaying those concerns and bringing disaffected Democrats back into the fold.

The $64,000 question of course is how does she do it. At this point, convincing Hillary backers that Barack Obama is the greatest thing since sliced bread will likely not do the trick. In fact, it's getting to the point where it's hard to imagine anything she says (or anyone else could say) that would convince recalcitrant Clinton supporters to get on the Obama bandwagon.

Instead Hillary's best approach is to take an opposite approach - namely scare the living hell out of them and make John McCain seem like the second coming of George W. Bush, Ronald Reagan, Richard Nixon, Herbert Hoover and Genghis Khan wrapped up in one malevolent political figure. The message from Hillary to her supporters needs to be "you may not like Barack Obama, but the alternative is a heck of a lot worse."

This means focusing on McCain's committed pro-life position and the risk to women of having McCain appoint the next Supreme Court justice. It means reminding voters that McCain's approach to foreign policy has generally been shoot first and ask questions later. It means making sure voters know that John McCain owns seven homes and can't remember that fact. And above it means telling her supporters, if you hated George W. Bush, you ain't seen nothing yet.

This approach may run counter to Obama's post-partisan message and his wife's maudlin, but effective performance last night, but someone at the Democratic convention needs to tear the bark off of John McCain - and Hillary Clinton is just the person to do it.