Just be honest. They always sucked. When it looked like they might be good they had to get them away from DC. At least these Nats had one good stretch of years.
The '67 team was getting good. That was the last Gil Hodges team. The 1969 team was a basis for something, but Bob Shorted traded Ken McMullen, and then traded Ellie Rodriguez, Eddie Brinkman, Jim Hannan, and Joe Coleman for Denny McClain. Pure sabotage of his team, which Short then took off to Texas in hopes of selling to some oil buzzards. Idiot. Bob Shorted Washington as Crazy George Allen vowed to get the Redskins into the playoffs. And the 1971 Redskins did. And the Washington Redskins became the most valuable sports team in the US, and probably the world, just then.
Washington was always baseball-crazy, and Short played in a big, new stadium in a market that was becoming bigger and wealthier in a town that was immune to recessions. He would have cleaned up with a good team. Idiot. (Of course, Calvin Griffith owned the team that owned Washington's heart. It took a while for the city to warm to the New Senators, to Frank Howard rather than Harmon Killebrew and Bob Allison. Calvin lost big-time by going to a small market just as the Senators got really good. Imagine Griffith's 1965 team playing at DC Stadium!)