Considering the recent results, it would be unusual if their fan base was not obsessing over the Patriots. They have now lost four in a row and five of their last six against the Pats, and before every one of those games they felt very confident that they would win.
Oct 20, 2008: Pats favored by 3
New England was favored by 3 at home, which means the two clubs were considered to be even. With no Tom Brady the Denver fans had high expectations for a win; the 4-2 Broncos had won five of their previous six games in Foxborough and the 3-2 Pats had been inconsistent all year. The Patriots forced five turnovers in front of a national (MNF) audience and opened up a 34-0 lead before Denver finally scored in garbage time; final score: 41-7.
Oct 11, 2009: Pats favored by 3
To rub salt into the wound, the last time Denver beat the Patriots they were coached by Josh McDaniels, a guy they ran out of town who is now working for the enemy (i.e., the Pats). Denver wins 20-17 in OT to advance to 5-0; after winning the following week they would finish the season 2-8. Every time they see McDaniels it is a reminder of a season they would prefer to forget.
Dec 18, 2011: Pats favored by 7½
This game was played at what was possibly the height of Tebowmania, as the Broncos entered the game on a six-game winning streak. Denver scored on their first three possessions, only to have the rug pulled out from under them after that. It's not just that they lost; it was that with that 16-7 lead early already high hopes reached a crescendo, and then came crashing to a shattering reality of a 41-23 loss.
Jan 14, 2012: Pats favored by 13½ (playoffs)
Although Denver was a huge underdog, their fans were full of confidence. Tebowmania was in full effect as they had just upset Pittsburgh in overtime the previous week. Their fan base was fully convinced that destiny was on their side and that they would win this game. A 45-10 loss put an indelible bruise on their collective psyche.
Oct 7, 2012: Pats favored by 6
Both teams were 2-2, so although the Pats were favored the Denver fans felt good about their chances as they now had Peyton Manning at QB - and the Pats were seen as being vulnerable having just lost back-to-back games to Arizona and Baltimore. The Patriots ran for 251 yards and jumped out to a 31-7 lead, but two late Denver touchdowns gave them hope for the next time with a relatively close 31-21 final score.
Nov 24, 2013: Broncos favored by 2½
Broncos enter the game 9-1, and all season long the biggest on-field topic of discussion nationally has been about how unstoppable Denver is. At halftime the Broncos are celebrating about not only defeating the Pats, but recalling 'call in the national guard' comments from a generation ago. From now until the next meeting, whenever they hear the word 'Patriots' it will remind them of losing a 24-point lead in front of a national audience, 34-31 in overtime.