The Secret Service has closed Pennsylvania Avenue in front of the White House to vehicles, creating the kind of security envelope usually reserved for tin-horn dictators. But a group of nuclear weapons protesters known as the Vigil fears that the frenzy to insulate the president from any and all dangers could lead to fencing in Lafayette Park, a safety proposal the Park Police floated at an April public meeting. “Closing the park won’t protect the president against bullets fired from outside the perimeter, and it won’t protect him from falling airplanes or bombs lobbed in by high-power catapults,” says Vigil co-founder W. Thomas, who fears that his group, which has maintained a 24-hour-a-day watch in this park since 1981, will be left without their prominent public forum. “The best way to insure a safe first home is to enclose it with a dome, similar to the one on the Pope’s golf cart, but much larger; something along the lines of the Astrodome.” Thomas suggests that a two-layer, thermoglass dome could absorb bomb blasts, and adds that the country should hold a contest to come up with the strongest, most aesthetically pleasing dome. Once the White House dome is perfected, he adds, the technology could be used to protect federal buildings all over the country. Maybe so, but what technology would protect the domes from pigeons?