So I was playing President Infinity and I noticed that in the 2008 scenario, the Republican Senator Chuck Hagel is a VP option for the Democrats, and the Independent caucusing with the Democrats Senator Joe Lieberman is a VP option for the Republicans.
So let's say that for some reason, in 2008, Chuck Hagel was nominated for President by the Democrats, and Joe Lieberman nominated by the Republicans. VP choices are yours.
Who wins?
Hagel would have won on the basis that he was the most anti-war candidate and people were very much weary of our involvement in Iraq.
That being said, Hagel was out of sync with just about all Democrats on economics, and Lieberman had been pretty much a pro-labor Democrat over the years. I see the possibility of either of them getting the opposite party's nomination as highly unlikely.