The value in tossing the bums lies in reminding them that they can be tossed. If you think that the “culture of corruption” will go away if only we’d elect the Right People, then you lost the plot long ago. Until you change the underlying incentives, the story will stay the same.
If the Democrats move to limit their own power and to change the underlying incentives, they’ll change the culture. If not, then they were never serious about getting rid of the corruption…they just wanted a piece of it.
UPDATE: Oops cut-and-paste error picked up the breakout quote and double-pasted. Fixed now.