Both Ryan and McConnell pointed to a recent House Judiciary Committee hearing in which Attorney General Loretta Lynch was asked about bringing Guantanamo prisoners to this country. “With respect to individuals being transferred to the United States, the law currently does not allow for that,” Lynch testified.

It appears Congress — not Republicans, not Democrats, but Congress — is on solid legal ground. A former George W. Bush administration lawyer who asked not to be named argues that Bush, at the end of his presidency, “acknowledged that the Constitution directly provides Congress with power over the treatment and prosecution of detainees.” Among those constitutional provisions are Congress’ power to “make rules concerning captures on land and water” and to “define and punish … offenses against the law of nations.”

“The Obama administration’s position would be met with very strong, contrary arguments based on both of those constitutional provisions, and the Spending Clause [Congress’ power of the purse], and the clause authorizing Congress to “make rules for the government and regulation of the land and naval forces,” the former official said in an email exchange.