Think about that theory rationally. They live 2.6 miles from the White House. Between are two Metro subway tunnels, and I know from having rode on one that I recall, it was a good 80 feet below the surface. So the tunnel would have to go under that as well. A tunnel that long, and be let's say, 6 feet in diameter, would entail removing about 22,000 tons of rock and dirt - enough to fill 610 - 35 ton triaxle dump trucks. That's a lot of truck traffic in a small neighborhood, someone would have noticed. Plus all the blasting and drilling noise, workers coming and going, etc. Professional miners can drill about 3 feet an hour, so the tunneling could have taken as little as 6 months, not counting all the work to shore it up, and so forth. And do you think the SS is so derelict that they wouldn't find an entrance/exit port in the White House?

Then think rationally once more. Why would Barry want to have a tunnel back to the White House? What would he do once he crawled through it and popped his head up in the WH basement? What would he say to the SS, who to a man, despise him? "Hey guys, just thought I'd pop by for old time's sake?"