[Robert DeLong]

Have Congress call him before them to answer questions about the organizations he supports. If he refuses he immediately becomes eligible for revocation of his citizenship. If he does come to testify any number of the organizations he supports financially can be deemed subversive making him eligible for revocation of his citizenship. 8>)

[oldasrocks]

Mr. Putin, buddy, pal, I need a favor. Please tell me you want Soros on a warrant.

[Buckeye McFrog]

Have Congress call him before them to answer questions about the organizations he supports. If he refuses he immediately becomes eligible for revocation of his citizenship

As a citizen he enjoys the Fifth Amendment right against self-incrimination. That's a complete non-starter.

You can't just wave a wand and revoke someone's citizenship. The ex-Nazis who lost theirs only did so after lengthy court battles.