Candidates and Elected Public officials investigated by the Bush "justice" Department from 2001 through 2006:
Democrats 298 (79.47%)
Republicans 67 (17.87%)
Independents 10 (2.66%)
So either Democrats are four and a half times more corrupt, or something else is going on here.
Intuitively it makes no sense that Democrats would be more corrupt during this period. They were not in power. For example, why would would anyone bribe a Democrat, who could not deliver legislation with any chance of becoming law?