Our highest level check was level 6 which cost a lot of money.
10 year employment check.
Complete education check.
Criminal and credit history check.
Address check.
Blood and hair sample drug tests.
5 personal and 5 professional references.
Discussions with your associates.
I got to do some of them, They were some high level executives and such.
And how many of these are required for the job of POTUS?