Washington has been eliminated from first place.

To show that Washington is eliminated from first place, we start with the current standings:
            Team	W	L	GL	PCT	GB
         Atlanta	94	68	0	0.580	0.0
    Philadelphia	88	74	0	0.543	6.0
           Miami	80	82	0	0.494	14.0
      Washington	77	85	0	0.475	17.0
          NYMets	74	88	0	0.457	20.0
           Total	413	397	0

Washington can finish the season with at most 77 + 0 = 77 wins and will finish the season behind the following teams:
Atlanta has already won 94 games.
Philadelphia has already won 88 games.
Miami has already won 80 games.
# Washington Nationals' magic number
# Washington's magic number
# Nationals' magic number
# MLB Playoff Race