Very interesting stuff. Stuff we've all suspected, but it's nice to get objective numbers for it.

Highlights:

* The previously most-polarizing political figure was Bill Clinton, natch. But Bill Clinton's partisan gap (the difference between support from his partisans and support from those in the opposite party) was only 60 points in May 1996. Bush's partisan gap is 25% larger, over 70 points of difference.

[Yeah, I know, that doesn't seem like quite 25%. But this is what Gallup tells me.]

* Bush's 70+-point gap is not only unprecedented for May of a re-election year, but it is unprecedented for any point in a re-election year. No president, dating back to Harry Truman, has had a partisan gap above 70 points in any Gallup Poll in a re-election year.

* Prior to Bush, there were only a few times when a majority of one party's supporters strongly approved of a president while a majority of the other disapproved. For example, during the last years of Clinton's presidency, Gallup found a majority of Republicans strongly disapproving of him and a majority of Democrats strongly approving of him, but never did both groups simultaneously exceed 6 in 10. The closest the groups came to matching Bush's current pattern was in March 1999 -- shortly after the Senate acquitted Clinton in his impeachment trial -- when 57% of Republicans strongly disapproved and 73% of Democrats strongly approved of Clinton. This was one of four times (out of nine measurements for Clinton) when a majority of Republicans disapproved of him at the same time a majority of Democrats approved.

The only other time Gallup data find a majority of the two parties' supporters holding strong opposing views of the president was in October 1982, when 51% of Republicans strongly approved of Reagan and 54% of Democrats strongly disapproved.

* While the polarization in the current president's approval ratings is certainly remarkable, the fact that such a high proportion of either partisan group has such strong opinions is also rare. The only other president to have more than 60% of a partisan group disapproving of him was Richard Nixon in the year of his resignation, when 61% of Democrats strongly disapproved of him. At that time, Nixon had overall job approval ratings below 30%.

Taken together, the data show that the current political environment is highly unusual. The country experienced a polarization only remotely similar during the Clinton-Lewinsky scandal years.

There are good reasons for this, I think.

There is Florida 2000, of course.

But there's also the fact that Bush has not been afraid to push his agenda hard, and the Democrats have been emboldened to resist just as hard, if not harder.

We all know what's going on: The Democrats have staked their political future -- their viability for 20 or more years -- on a disaster in Iraq and in the American economy. They have not been careful to half-support Bush's moves, so that they can take partial credit if good news comes. They have stridently opposed just about everything he's done, so that if there is good news, they will be discredited.

They cannot afford, at this point, for America to win in Iraq. Or for America's economy to recover.

The stakes of this election, then, are pushing both sides to historic levels of partisanship. But it's particularly vicious on the left, which has, of its own free will, set itself up so that it can only prosper politically should America be beset by misery and disaster.

In a way, I can't even blame the left anymore. They may have put themselves into this situation, but however they got there, they're in that situation now. They cannot under any circumstances afford for Bush to preside over the rapidly-growing, super-prosperous, Treasury-enriching 2005-2009 presidential term.

And if that means they need terrorist attacks, dead American bodies in Iraq, and Hoovervilles, so be it. They've got to pray for those things. They've left themselves little choice.

Even though they opposed the tax cuts which were partly responsible for the new prosperity, they can at least take credit if the economy grows like gangbusters under President John Kerry. It happened under my watch, he will say.

This is going to be a watershed election. The consequences of this election will be felt for 20 years.