Selecting Tom Vilsack or Dick Gephardt (instead of John Edwards) would definitely have helped narrow the gap a little electorally -what would have helped even more is if Kerry had decided not to suddenly abandon West Virginia in the middle of the campaign.
First, at the time, I said Kerry should have done two things: A. Abandon FL; B. Fight in WV.
Gephardt would have probably been the better candidate. He would have had fairly strong appeal in WV, IA, and OH. MO is also a possibility. Gephardt probably would have helped in PA, which was reasonably close, but Kerry would not have had to expend as much resources here to win. A combination of not contesting FL and Gephardt on the ticket could have been a winning combination.
Kerry made a number of strategic errors in the campaign and one of those is named John Edwards.