Milwaukee has always been a second-tier airport, with many people in southern Wisconsin choosing to drive all the way to Chicago’s O’hare or Midway airports to get cheaper airfare. But recently discount flier AirTran Airlines has established Milwaukee as a “focus city”, and one holding company has bought up both Milwaukee-based Midwest Airlines and Denver-based Frontier Airlines, and added more Milwaukee service by the latter. But the biggest news in cheap airline tickets for Milwaukee is the initiation of service this week by Southwest Airlines, the undisputed master of low fare airline travel. Everybody in Wisconsin is going to be able to take advantage of this.