I guess Cruz doesn't want to be elected.
FTA: The language of the press release, Cruz himself, and the other Republicans were clear, indicating that they do not believe that Americans who have refused the COVID-19 vaccination deserve to have their previous normal lives restored. They also offered no support for the rights of those who have naturally acquired immunity from the virus, which is at least as effective as the vaccine or better.
Link to article: https://bigleaguepolitics.com/ted-cruz-other-republicans-call-to-force-masks-on-unvaccinated-americans/
The US Constitution forbids any law singling out Americans for ANY purpose.
This proposal is a blatant violation of the US Constitution.
However, being that it is coming from a completely illegitimate government should not surprise anyone.