After a promising start to the weekend (a 4-1 win on Friday night), the Nationals dropped back-to-back games to the Cardinals in all too familiar fashion: Back-to-back 6-0 losses to the best team in baseball, and consecutive no-shows by the Nats’ bats. Saturday, the Nats had no answer for the previously struggling Jason Marquis, managing just two hits. Yesterday they collected just four hits and two walks. It all adds up to another series’ loss…