In 616 a campaigning politician tried to get Cap's endorsement, and Cap refused in a polite way. This was during a period where all Marvel's US pretty much worshipped him. When Cap was tied up in a closet while a flamboyant Skrull impersonated him, the Skrull gave an endorsement to that same politician. After that had been resolved and the politician was suffering from that, Steve felt bad, so as Cap he exposed the politician's opponent's ties to (I think) Hydra, and since he liked the politician's policies he went and stumped for him as Steve Rogers.

I do think that's a pretty definite way of showing that while Steve has his opinions on politics, he's not willing to let anyone take his image. I liked those issues...