Why is Harry Reid rebounding?

Harry Reid was a lost cause. Both Minority Whip Dick Durbin and Chuck Schumer have been publicly vying for his position for over a year now when it is assumed he will be defeated for reelection. Not so fast, says a recent Mason-Dixie poll recently released which shows his numbers rebounding significantly. Reid slightly trails potential challengers Sue Lowden and Danny Tarkanian and actually LEADS Sharon Angle. These are not good numbers for an incumbent by any means, but they indicate a competitive race. So my question is, what has caused this sudden reversal of fortune. The surge can be attributed to several factors.

1. The Republican field- The Republicans have fielded a very poor assortment of candidates in this race. Danny Tarkanian has no political experience at all, Sue Lowden is the Nevada GOP chair, and Sharon Angle is a former state assemblywoman. Sue Lowden, the presumed front runner, has been bogged down by numerous gaffes since launching her campaign. The most famous of these is when she suggested bringing chickens to healthcare providers was a good way of bringing down costs. Sharon Angle is the Tea Party favorite. Like many people conservative enough to be Tea Party affiliates, they do not match their electorate. Nevada is a swing state. Being associated with a right wing organization does not help you with the general electorate.
2. The immigration debate- This is where most pundits have fallen short. The bounce comes as an extensive immigration bill is introduced into the Senate with widespread Republican opposition. This clearly drove Hispanics to Reid's camp in large numbers.
3. Reid's war chest- Very, very large. It was $11 million at the beginning of the election season, but could now be as much as $25 million. Hard to top these numbers.

On top of all these factors, Democrats have been rebounding slightly in national polls. They hold the generic ballot once again, are surging in swing states, and are finally deploying a messaging strategy. If Harry Reid is not defeated for reelection, it will be very difficult for the RSCC to peel off other swing states.