Via the Hotline, a hopeful history lesson by Steve Lombardo at Pollster.com:
The trend from 1988 – 2004 shows that the GOP candidate tends to under-poll in the summer–with the exception […] of the 2000 campaign. In each of the other four years, the Republican candidate had been polling significantly behind the Democrat at this point in the race. Each of those times, however, the Republican improved his position, gaining an average of 15 points relative to the Democrat.
