Congressional Democrats on Tuesday tried but failed to pressure Republicans into seeking President Donald Trump’s tax returns, saying the scandal over Michael Flynn made it imperative to find out whether the president has business ties to Russia. A day after the Republican chairman of the House of Representatives Ways and Means Committee dismissed the idea, the panel’s Democrats proposed an amendment demanding that the committee ask the Treasury Department for copies of Trump’s returns by March 1. “Unless this amendment is adopted, we will never see the president’s tax returns while he’s in office,” Representative Sander Levin, a Michigan Democrat, told committee Chairman Kevin Brady at a public hearing.