No they do not !
No candidate does, the act of electing someone gives them the security “vetting” be they congress-pig, senator-creep or pResident! That's why elections are important and voting to deny power is as important (maybe more so!) then voting to give power.
Read the Constitution! You see any procedures for security vetting? The Founding Fathers actually thought we would take elections seriously!
Anyway think about it, what politician would put himself at risk for a security clearance. If the clearance process uncovers anything that is is illegal the investigators are bound by law to report it. Also the “party-out-of-power” could claim that the “party-in-of-power” was denying clearances to their candidates. How would it proved that wasn't that case? In today's political world it would happen!
We are reaching a third world level of political corruption and their is no cross party consensus against it. Also the public mouths platitudes about being against it but does little, particularly at the state, county and local level.
We desperately need term limits (a decade in an elected office is enough!) at all levels, its not a panacea, but at least it makes corruption more complicated to undertake.
We desperately need term limits (a decade in an elected office is enough!)...A decade in any one office is too long! Two terms is plenty; the house, two 3 year terms, two 4 year terms in the senate. No exempting themselves from any of the laws they pass; no retirement fund or medical except that which any of us can get if we choose to do so.