Once again, as in previous threads, it's quite apparent that a lot of you make the same mistake that computer geeks make when evaluating software/devices etc. They assume that the average consumer thinks like them and evaluates like them.
The average voter does not give a crap about the inner workings of congress, about what was set to expire, why and when, and other such technicalities. Do you think the average joe cares about 41 senators, filibusters, reconciliation and all that jazz?
That's all interesting stuff for us to discuss, but the bottom line is that when the average voter gets kicked in the nuts (ie, the wallet) and their taxes go up, they are going to blame whoever they think is "in charge", and that generally starts with the party in the white house, whether or not it's warranted. Just like the president gets blamed for "the economy" when he generally has fairly little actual control over it.
The repubs realize this, and they know that if everyone's taxes go up, they're going to very easily use the spin machine to blame "the usual tax and spend liberals, starting with Obama". As we're already seeing now, when the economy sucks, that is a VERY effective tactic.