What a difference three weeks make!  In CNN’s poll of Republican primary voters taken September 23-25, Rick Perry led Mitt Romney by 8 points, 30/22, with Newt Gingrich in a distant third at 11%.  In their poll taken over the weekend, Herman Cain has gone from 9% to leap into a virtual tie with Romney, who edges Cain by a single point at 26/25, while Perry drops to third at 13%.

However, only a third of Republicans have made up their minds as to how they’ll cast their vote:

One day before a CNN Western Republican presidential debate, a new national survey indicates that Mitt Romney and Herman Cain are essentially tied for the lead in the race for the GOP nomination, with Rick Perry dropping to a distant third.

But according to the CNN/ORC International Poll released Monday, only one third of Republicans and independents who lean towards the GOP say their minds are made up. …

“With only 33% of all Republicans saying that their minds are made up, it’s far too early to say the race is over, or even that is has boiled down to a mano-a-mano fight between Romney and Cain,” says Holland.

The survey indicates that most Republicans say they are satisfied with the field of GOP candidates still in the race, although only one in five describe themselves as very satisfied. Republicans who back the tea party are more satisfied with the field of candidates than Republicans who are neutral toward the tea party.

More importantly, the poll shows that the enthusiasm gap between Republican and Democratic voters continues to expand.  Almost two thirds of Republicans describe themselves as either extremely or very enthusiastic about voting in 2012 (38% and 26%, respectively), a slight increase from June’s results (38% and 23%).   To get the context of those results, a CNN poll taken just before the midterm election last year showed enthusiasm in these categories at 29% and 25% — and the GOP won 63 seats in the House and six in the Senate.

Democratic enthusiasm has moved in the opposite direction.  The new poll shows 21% and 22% extremely or very enthusiastic about voting, respectively, which puts the combination below a majority for the first time since the midterms.  In June, those figures were at 26% and 29%.  The gap between total significant enthusiasm between  the two groups has moved from an R+5 in March to an R+6 in June and now to an R+21 in October.

It’s worth noting that this is after Barack Obama’s attempt to generate base enthusiasm with his class-warfare rhetoric and Potemkin jobs bill.  If this strategy is working, it’s only because Democratic enthusiasm would otherwise be crashing through the floor.  It looks like Obama’s exciting the fringe while discouraging everyone else on his side, and since this strategy is almost designed to lose independents, it’s difficult to see how Obama expects to win another term.