All joking aside, I really don't know how important an endorsement by Joe Lieberman will be for John McCain.

Sen. Joseph Lieberman (Conn.), who was on the national Democratic ticket in 2000, will cross the aisle to endorse Sen. John McCain (R-Ariz.) tomorrow, Republican sources said.

The two will appear together on Fox News on Monday, then at an 8 a.m. town hall meeting in Hillsborough, N.H. They will talk with reporters after the meeting. McCain is also scheduled to appear on NBC's "Today" program.

The move, which will help cultivate McCain's moderate status, is an effort to draw attention to the McCain campaign, which needs a splash. Otherwise, it does not make sense for McCain because it will only remind core Republicans why they distrust him.

I have to agree with that assessment. When push comes to shove, Lieberman is the last of the Scoop Jackson Democrats. His endorsement would make great sense in the fall, if McCain were the nominee. But how does the endorsement of a liberal Democrat really help John McCain in the GOP primary, unless it manages to pull in new voters to the GOP process -- something unlikely to happen in large enough numbers to get make the negatives among the GOP base go away.

And I say this as someone who admires Joe Lieberman and would love to see more like him in the Democrat party.

What this endorsement does do, however, is make McCain a viable GOP VP choice -- but then again, he already was. Or, as an extreme long-shot option, it creates the possibility of a McCain-Lieberman independent run that would draw from the political center. After all, if Americans are really so disillusioned with the direction being taken by both parties this year, such a bi-partisan ticket could draw centrist voters.