Sen. Mitt Romney (R-Utah) said on Thursday that he will oppose President Trump's emergency declaration to build the U.S.-Mexico border wall. "I will vote today for the resolution of disapproval. This is a vote for the Constitution and for the balance of powers that is at its core," Romney said in a statement. Romney is the sixth Republican senator to say he will vote for the resolution of disapproval, which is getting a vote in the Senate later Thursday.