A person who is a national of the United States whether, by birth or naturalization, shall lose his nationality by voluntarily...

making a formal renunciation of nationality before a diplomatic or consular officer of the United States in a foreign state

You have to be outside the US to renounce. Deportation is not the US's problem.

But yes, that's one of the big issues of statelessness they can't send you back anywhere.

Edit: second half the quote was not formatted as a quote. fixed