For one thing—and this cannot be emphasized enough—it is not her money. If the Landrieu family has great love for the Portmans and wants to donate some of its personal funds to his re-election, the political optics might suck, but there would be no legitimate complaint. It'd be their cash, after all.

But this is not Landrieu's personal wealth that is being dangled in front of the Ohio Republican. It is money that had been donated to her, the overwhelming bulk of which came from Democrats who hoped (alas, in vain) that her re-election could help save a very tenuous Democratic majority last year. One has to imagine that many of those who donated to her campaign would be less than thrilled to see Landrieu offering aid to a Republican who is now critical to maintaining GOP control of the Senate.

For another, Landrieu gives the vital appearance of bipartisan honor to a senator whose voting history is nowhere near middle-of-the-road. Every incumbent in a competitive race yearns for the ability to look like a bridge-builder, especially at a time when the popular conversation has little more than contempt for "politics as usual." Portman is no centrist, except perhaps when viewed through the lens of a deeply conservative GOP: His two decades-plus in DC confirm that. But a seal of approval in this case from Landrieu would give him an undeserved patina of bipartisanship and moderation, which could matter a great deal in a race as close as a prospective Portman-Strickland battle promises to be.

What Landrieu is proposing to do is utterly unacceptable, and even publicly proposing it in the first place is obnoxious and insulting in the extreme to her supporters. It's embarrassing that she doesn't appear to know any better, and what does it say about Landrieu that she now wants to help the party that brutally savaged her while turning her out of office last year? Nothing good, that's for sure.