WASHINGTON (Reuters) -U.S. President Donald Trump's signature tax break on tips promises relatively few upsides for low-income Americans, who face a net loss of income under his massive tax and spending bill in Congress, analysts say. The new tax break is one of several aimed at helping working-class Americans who are a key bloc in Trump's political coalition. "If you're thinking about things that could help low-income workers, 'no taxes on tips' would not be high up on my list," said Martha Gimbel, director of the Budget Lab at Yale University.