DETROIT — Two former chairmen of the Michigan Republican Party are throwing their support behind the effort to make the state one of the earliest to cast ballots in the presidential primary calendar. Republicans Saul Anuzis and Rusty Hills sent a joint letter Monday to the Democratic National Committee’s Rules and Bylaws Committee, which is weighing applications from Michigan and 16 other state parties competing for one of the coveted five early spots in 2024. Anuzis and Hills in the letter said the battleground state best represents the country’s demographic and economic diversity that both R…