With midterm elections less than four months away, Republicans are fired up and ready to go. But they are not the only ones upset with Barack Obama. The president has also angered many of the key Democratic constituencies he needs to keep control of the House and Senate, and now Democrats are blowing furiously on the fading embers of their electoral coalition, hoping to stave off disaster this November. Unions are incensed with Obama and congressional Democrats for their failure to deliver on key priorities such as card-check legislation. Another disenchanted constituency is Hispanics. Latino support for Obama has dropped...