Politics: The president tells building-and-trades union workers that Republicans have blocked multiple bills putting them to work, even as he blocks an oil pipeline their former union chief supported. President Obama may have thought he was preaching to the choir when he addressed the AFL-CIO Building and Construction Trades Department Legislative Conference on Monday, blaming Republicans for blocking his attempts at job creation. But he forgot one of the cardinal rules of public speaking — know your audience. "I've said now is the time to do this, interest rates are low, construction workers are out of work ... and time...