Cruz.
Some of the things he has done lately seem so out of character to me @Sanguine
I'm not sure why it would be out of character for a Constitutional lawyer who has argued before the USSC several times, and now sits in the US Senate, to express an opinion on the constitutionality of a proposed act of Congress.
In fact the USSC ruled in Myers v. United States that the president has the sole, unilateral authority to fire an executive branch official, and needs no approval from the Senate to do so, regardless of whether the Senate had confirmed the original appointment. In the same ruling the court determined that the Tenure of Office Act, which had been the basis of Andrew Johnson's impeachment and had itself been repealed some twenty years later, had been unconstitutional.
I'm no attorney myself, but I don't see any condition under which Cruz could be incorrect.