This year the state legislature tried to close a revolving door. In 2007 Congress tried to close their version of that door. I’m not sure how well either of them will work over time, but if it’s important to close revolving doors, maybe we should try closing another revolving door – the one from one federal elective office to the Presidency.
Admittedly, few sitting legislators have been elected as President, but you have to go back to 1900 to find a presidential election where a Senator did not seek the presidency (there were generally members of the house seeking it as well). Maybe if we placed a two year restriction after leaving a federal legislative office before a person could seek the presidency we might have fewer members of Congress trying to use their offices as stepping stones to the Oval Office.
Of course that would simply guarantee two year presidential campaigns, but at least those campaigns would not include a guaranteed fallback of a seat in the Senate for sitting senators.