WASHINGTON (Reuters) - A senior Democrat on a congressional panel seeking President Donald Trump’s tax returns warned on Saturday that the current Congress may not see the long-sought tax documents without launching an impeachment inquiry. Representative Lloyd Doggett, who sits on the House Ways and Means Committee, said Democrats, who control the House of Representatives, were slow to request Trump’s tax returns from the Internal Revenue Service and now need to push back forcefully against Trump’s refusal to turn over the returns. “Because this request was delayed until April and no legal action has yet been filed to get the...