Less than a month ago, Texas Democrats turned out in huge numbers for the presidential nominating contest between Hillary Rodham Clinton and Barack Obama, confident that, no matter who won, the party would have a popular, well-financed candidate. But that exuberance is gone now. Across the state this weekend, tense confrontations -- even shoving matches -- erupted as partisans for Clinton and Obama battled over how to interpret the March 4 election results and how to choose delegates to the Texas Democratic convention. At one particularly raucous session Saturday at Texas Southern University, a leading Clinton backer, U.S. Rep. Sheila...