WASHINGTON — Are y'all set for the sartorial splendor of today's summer seersucker spectacle in the U.S. Senate? "It's a Southern thing," said Sen. Trent Lott (R-Miss.), organizer of the bipartisan show of stripes. "But it has spread far and wide — from sea to shining sea." On the Senate floor, the cool, crisp cotton fabric will be the fashion order of the day. And the seersucker suits will cross gender as well as party lines. Sen. Dianne Feinstein (D-Calif.) has arranged for women senators to join their male colleagues in this rite of the season. "Things have been pretty...