If Clinton gets in (likely), Obama's last act in office should be to give her a blanket pardon for any and all crimes and note that the Republicans have no grounds to impeach her until she actually starts. If his sense of humor is kicked in, he could say the pardon is unnecessary, based on years of investigation, but that this is just a budget balancing tool to save 10's of millions of dollars that would be otherwise wasted. It's likely that the Repubs would wold start squawking about how "Criminal Hillary needed a pardon for her myriad crimes" (well, they probably wouldn't say "myriad" because of the limitations of their base, but...) and a reasonable person could respond that it was necessary because her "loyal opposition" would investigate a grilled cheese sandwich, made with Velvetta, for ties to the dairy industry.

from Terry Pratchett's diskworld. Didn't want to be a spelling nazi, but since you asked...