I guessed that was the case for you, but I've seen the phrase used in a few other places and I have a feeling many are not as self-aware :-)

Well, that would be evidence that it is quite extricably linked to the Trump campaign.

There is prior art for campaign slogans escaping the political world and transcending their original partisan meanings. "A chicken in every pot", "Don't Mess with Texas" ("slogan that began as anti-littering campaign; later adopted for political and other purposes" - Wikipedia), etc. Wikipedia also suggests it has been used prior to Trump, including by both Bill and Hillary Clinton (https://en.wikipedia.org/wiki/Make_America_Great_Again ).