This is because Democrats believe in higher taxes (actually, redistribution of wealth), while Republicans believe in lower taxes. Unfortunately, the Republicans have never been able to reduce government spending to match their lower taxation plans and, therefore, deficits rise. Whether this failure is because Democrats prevent them from cutting spending, or they are secretly another party of Big Government, or because the constituency prevents it, doesn't really matter. The only way to solve the deficit problem, and deal with taxation, is to force a balanced budget amendment upon Congress. Otherwise, they will collectively choose deficit spending rather than cut spending or raise taxes.