Most of the press scrutiny on Carter in 1980 was about the Iranian hostage crisis, but the press would also call him rude. He was never a great public speaker so compared to Reagan reading lines perfectly, he sounded like a goofy hick stumbling through his words. Also when I say rude, I mean Carter would sometimes say Reagan was racist or a warmonger. Carter was correct, but in 1980 that was considered beyond unacceptable to say about a political opponent.

Carter was unpopular among both libs and conservatives in 1980 though, which is how Ted Kennedy got so close to the nomination. Also the parties also weren't fully unified nor ideologically coherent in 1980 by the way, so they didn't have separate media spheres. That didn't start to happen until the 90s. The "red state blue state divide" didn't even happen until 2000