"If they send the Army into New York and you have 10,000 troops marching carrying semi-automatic weapons, I think it's a terrible image," Sen. Rand Paul said.

The senator said he would "not support and will not vote to use the military in our cities," adding that he thinks "it's a terrible image."

Trump's plan to use the military for mass deportations faces sharp legal limits. The administration's few options come with major potential blowback.