First, Michigan law does prohibited those convicted of "felonies" "that breach the public trust." Never been clearly interpreted - quite a controversy last year when a Detroit Dem who had been convicted of armed robbery ran.
Let's fine tune this opinion - I agree that generally convicted Felons shouldn't be allowed to run. Working on state law first (which should generally be copied to federal law).
First, let's define that, since "breach of the public trust" is so flimsy as to evade definition, as last year proves.
I'd start with a short list for sures - murder, violent crime, etc., then add crimes that "put other individuals in direct danger", convicted of any crime DURING office regardless of the crime, and economic crimes that harm the public. This is off-the-top of my head - it should be tweaked.
For CERTAIN OFFICES, the Attorney General, Sheriffs, Judges, and Prosecutors, I'd make it almost any crime including almost all misdemeanors. Top law enforcement officers (witness Eliot Spitzer) must be held to a different standard precisely because of the type of job. Erosion in the confidence of the justice system occurs when these positions become even slightly corrupted.
At the federal level, some Constitutional amendment should be devised along similar lines, but, like Term Limits, you can bet no Congress any time soon is going to vote for one (might as well do Term Limits along with it - I'd agree to relatively long limits in such a situation).
Chetly Zarko
Outside Lansing & Oakland Politics