WASHINGTON (Reuters) - A partial U.S. government shutdown over President Donald Trump’s demand for $5.7 billion to build a wall along the U.S.-Mexico border entered its 22nd day on Saturday, making it the longest shuttering of federal agencies in U.S. history, with no end in sight. Trump, holed up in the White House with Congress adjourned for the weekend, warned of a much lengthier impasse and blamed the Democrats. “We will be out for a long time unless the Democrats come back from their ‘vacations’ and get back to work,” he tweeted.