Early voting began Thursday and continues Friday in Oklahoma City’s mayoral race. Registered voters who can’t get to the polls Tuesday can vote early at election boards in Oklahoma, Cleveland, Canadian and Pottawatomie counties. About 300,000 Oklahoma City residents in the four counties are eligible to vote in Tuesday’s election. Mayor Mick Cornett is seeking a fourth term in a four-way race. His main challenger is Ward 2 Councilman Ed Shadid. If nobody gets a majority, the top two finishers advance to a runoff April 1.