Arizona's 11 Electoral College members unanimously voted for Republican Donald Trump.
The meeting of the electors Monday at the state Capitol came as members were inundated with emails, hundreds of letters and untold numbers of calls urging them not to cast their ballots for Trump.
The same pressure was being placed on Republican electors across the nation.
About 150 protesters marched around the Capitol mall in opposition to Trump.
They carried signs that said, "Stop Trump," ''Our electors should be our protectors" and "Hand picked by Putin - what could go wrong."
The electors are all Republicans because Trump won the Arizona election with 49 percent of the vote compared with Democrat Hillary Clinton's 45 percent.
They were picked by the state party.