Harry Reid faced token opposition as an long time elected incumbent, this not an equal situation.
I'm not talking about late March, I'm talking about now and it's not top news right now. Rasmussen had Mack leading in Florida, then back tracked weeks later with in down more than a few points. Rasmussen is playing with numbers again.
Actually, the same exact poll had Obama up 8 points. Rasmussen is presenting the poll and you're making up excuses.
Of course, the 2004 situation is about as close as equal as one is likely to get. Dean Heller has been elected already by the people of Nevada.