Fox News Channel dominated the coverage of the Arizona and Michigan primaries Tuesday night.Cabler drew 2.3 total viewers in primetime, besting both CNN (1.1 million) and MSNBC (1.1 million). That was also the order in the news-friendly 25-54 demo. Ratings are expected to increase for the political cablers as the Republican primary process continues toward the presidential general election. March 6 marks Super Tuesday, when 10 states are in play. Mitt Romney easily won the Arizona primary and narrowly edged Rick Santorum in Michigan.