No, they’re not. If anything, the distinction should be more clear for these entities than other private businesses who could at least be contracted by the government. Political campaigns are entirely private marketing arrangements. The extent to which they are “quasi-government” should be perfectly obvious in light of their intentions, which is to become elected in the future. Even if the candidate is serving in office, that office’s duties and the campaign they run are separate projects. There is no blurry line here.