An endorsement from Joe Rogan is probably better than an endorsement from all the late night tv talk show hosts. He is a pioneer in the podcast field, and has a very large audience. Not only is his audience large, it is probably mostly composed of the kind of independent voters that candidates need to get.
Furthermore, Rogan is a Hollywood celebrity. A minor one, but still he is connected to Hollywood and entertainment. For him to not be afraid of endorsing President Trump means there is a lot more support for the president than it appears in California.
Correct.