According to Tennessee Senator Bob Corker, Republicans know they're going to have to raise taxes on the wealthy, but they're looking forward to using the debt ceiling to hold America hostage again:

The Republicans know they have the debt ceiling, that is coming up around the corner, and, the leverage is going to shift, as soon as we get beyond this issue. The leverage is going to shift, to our side where hopefully we’ll do the same thing we did last time and that is if the president wants to raise the debt limit by $2 trillion we get $2 trillion in spending reduction and, hopefully, this time, it is mostly oriented towards entitlement and with no process.

I'm not sure the American people want to see another hostage situation—especially if it results in Medicare cuts. But, you know, if Republicans want to test that theory, they're more than welcome to.