WASHINGTON — A triumphant President Donald Trump and jubilant fellow Republicans celebrated the passage of their $1.5 trillion tax overhaul Wednesday as a "historic victory for the American people." The American people, however, will need some convincing.As Trump and GOP lawmakers gathered at the White House to cheer their first major legislative achievement — and the biggest tax changes in a generation — some Republicans warned that the party could face a painful political backlash against an overhaul that offers corporations and wealthy taxpayers the biggest benefits and triggers the loss of health care coverage for millions of Americans.There was no hint of anxiety at the White House, though, as the president and congressional Republicans pushed any qualms aside and reveled in a much-needed win at the end of a year marked by GOP infighting and political stumbles."We are making America great again," Trump declared, personally thanking his "little team" of Senate Majority Leader Mitch McConnell and House Speaker Paul Ryan, before lawmakers lavished praise upon a president they have often openly criticized."I don't know if we'll have bigger moments, but we hope to," said Trump.The president was expected to sign the bill at a later date for technical reasons. In fact, the signing may be postponed until the start of the new calendar year in order to delay $120 billion in automatic cuts to popular programs such as Medicare and spare Republicans from having to explain them in an election year.The tax package provides a deep cut in the corporate rate, from 35 percent to 21 percent.