Don't tell us that Joe Lockhart, former President Clinton's spokesman and a major player on the Democratic PR front, didn't think his party's takeover of the House was in the bag before Election Day. Want proof? The day after the Democratic victory, he bought a sprawling $3.1 million house in the city's Tony Kalorama section near Dupont Circle. It's huge: three stories, 4,168 square feet with three fireplaces, five bedrooms, and 3½ baths. One who's been inside says, "What's he need all that space for?" Lockhart, a founding partner in the Glover Park Group, richly connected to Sen. Hillary Rodham Clinton's presidential campaign, isn't talking. "I learned a long time ago," he E-mails, "to keep my mouth shut about things like this."