It’s Washington’s own version of The Big Dig, but it’s much more secluded and (hopefully) isn’t filling up with water. It’s a multi-million dollar boondoggle that provides plenty of fodder for Congresscritters who wish to howl about federal spending. It’s the Capitol Visitor Center, which has been under construction since 2001, and has increased in cost from $265 million at that time to $573 million today—which isn’t too bad for a Federal project, right? The…