A week after his Twitter debut, “30 Rock” star Alec Baldwin tweeted heavily about politics and 2012 presidential contenders, possibly indicating that he himself will run for office in 2012. The actor, who said earlier this year that he’s “very, very interested” in a political position, is rumored to be leaving “30 Rock” when his contract expires in 2012, just in time for the election. “I want to take the opportunity to state that although my days on network TV may be numbered, I hope ‘30 Rock’ goes on forever,” Baldwin wrote in a Huffington Post piece in April. Baldwin...