I would too but they are legally disqualified from holding office according to Article 6 clause 3 and Article 4 section 4 of the constitution. Yes, you can argue that Republicans also violate these parts of the constitution and they still hold office but this is because they uphold Capitalism and are supported by Capitalists with significant power. I guarantee you these would be used against a genuine Communist candidate because they do not have such powerful support and actively oppose the system that creates that power.

There is also the Communist Control Act which has admittedly been somewhat gutted but I don't believe for a second there wouldn't be bipartisan support for bringing it back the moment Communists become a real political threat.

Our efforts would be expediated if people like you joined the cause and supported revolution instead of waiting for it to fall into your lap.

To quote the lovely Mrs. Luxembourg, "It’s not that we fear for socialists the dangers and the difficulties of ministerial activity; we must not back away from any danger or difficulty attached to the post in which we are placed by the interests of the proletariat. But a ministry is not, in general, a field of action for a party of the struggle of the proletarian classes. The character of a bourgeois government isn’t determined by the personal character of its members, but by its organic function in bourgeois society. The government of the modern state is essentially an organization of class domination, the regular functioning of which is one of the conditions of existence of the class state. With the entry of a socialist into the government, and class domination continuing to exist, the bourgeois government doesn’t transform itself into a socialist government, but a socialist transforms himself into a bourgeois minister." [source]