could you really ask a beat cop to arrest the President? Could he ever consider his job safe after that?
Yeah you 'could' ask a beat cop to arrest the POTUS but the Secret Service just may take offense to such an (cough) 'aggressive action'.
As to the cop's job being 'safe' - I don't think a dead body full of 9mm bullet holes from the S.S.'s MP5s can put in a full day's work.
So no, his job wouldn't be 'safe'. 