A coalition of former Republican-nominated U.S. attorneys including two from Florida spoke out against President Donald Trump’s unsubstantiated claims of voter fraud in the presidential election, saying the country’s “very legitimacy as a nation of laws, not men, depends on getting this right.”

The letter, signed by 19 ex-federal prosecutors, came as Trump falsely and prematurely claimed he  won the election even as votes in several key states were being counted. The president suggested he would take an election case to the U.S. Supreme Court, although legal experts are dubious about what that path would look like.