Demagoguery
If it is true that the Republicans are refusing to negotiate any kind of tax increase whatsoever, then they are being stupid. In times of rising state deficit, governments raise taxes. That's what they do. That's what Margaret Thatcher and Geoffrey Howe did in the (in)famous budget of 1981, one of the loci classici of Thatcherite history and one of the most fiercely debated budgets in history. Margaret Thatcher's own account is freely available. Taxes are cut when revenues increase and budget deficits decrease. To insist on no rise of any kind in taxation is to delude your own followers, because some way, tax income will have to rise. If if is not done by direct raises it will be done by letting inflation gallop while keeping allowances and tax rates unchanged, which will be a lot worse than a clear and announced rise in taxation.