It could have been Jesus Christ himself on the ticket and the Republicans were going to make attacks. I think the media would have fawned over McCain and given Kerry props for "bipartisanship." It might all be horseshit, but I believe it would have been very effective.
What problems with the base? Maybe Nader pulls more votes, but I don't know one Democrat who was EXCITED about Kerry. We all voted for him anyway. I don't think McCain would have made me less excited about a Kerry Presidency. McCain would have been a terrific coup.