You aren't going to get anywhere unless you run as a Democrat or a Republican. Full stop. You might get on a local town council as a Communist or something, but if you actually want to change things? Pick a party.

Look at "Independents".

Out of 100 Senators there are THREE who don't identify as Democrats or Republicans. One of them will be gone after the next election and frankly, she deserves it.

435 Congressmen. All of them are Democrats or Republicans.