If it were anyone other than Goldman Sachs making the prediction, maybe we would believe it.In a news-making forecast, the bank says Republicans' plan to trim $61 billion ??? out of an estimated deficit of $1.5 trillion on spending of $3.8 trillion ??? could lower U.S. GDP growth by as much as 2 percentage points as the year goes on.This nonpartisan study proves that the House Republicans' proposal i