Ric Williamson and his fellow transportation commissioners will find themselves in a tight corner today as they meet in Austin to decide who will build the State Highway 121 toll road. On one level, the commission is simply fulfilling its duty as the Texas Department of Transportation's governing board by deciding whether to award a multibillion-dollar contract to Spanish construction firm Cintra or give it to the North Texas Tollway Authority. But a whole lot more is going on at another level. The Highway 121 decision also pits Mr. Williamson's desire to support Gov. Rick Perry's ambitious highway-building agenda against...