[MplsSteve]

With only one exception, McConnell has never broken 60% in any of his general election match-ups.

Here are his final winning percentages:

1984 - 49.9%
1990 - 52.2%
1996 - 55.5%
2002 - 64.7%
2008 - 53.0%

[deport]

This particular poll had an identified party percentage as follows:

50% Democrat
39% Republican
11% Independent

Ultimately as you point out the race will most likely be close regardless of who wins.