President Joe Biden celebrated Independence Day with an optimistic tweet as he prepared to host military families for a barbecue at the White House and fireworks on the National Mall. With the national mood soured by soaring prices at the gas pump and the grocery aisle, Biden sought to put a hopeful stamp on the July Fourth holiday weekend. “Make no mistake, our best days still lie ahead,” Biden tweeted. Biden called the Fourth a “sacred day” with a special only-in-America meaning for all of us. “The Fourth of July is a sacred day in our country,” he said. “It’s a time to celebrate the goodnes…