By Richard Cowan WASHINGTON (Reuters) – The U.S. Congress is struggling through another contentious week as infighting over defense spending, healthcare and other matters complicates the drive to pass a temporary spending bill by midnight on Friday to avert a partial government shutdown. In a week when President Donald Trump and his fellow Republicans in Congress are hoping to celebrate the passage of tax overhaul legislation, many in the party showed little appetite for a government shutdown at week’s end. “I’m going to vote for whatever I need to, to keep the government open,” Republican Representative Chris Collins told reporters.