2012 Election Pew Research Polls
9/22-10/4/2011 1901 Registered Voters +/-3 MOE 48 Obama/48 Romney
11/9-11/14/11 1576 Registered Voters +/-3 MOE 49 Obama 47 Romney
1/11-1/16/2012 1207 Registered Voters +/-3 50 Obama/45 Romney
2/8-2/12/2012 1172 RV +/-3 52 Obama / 44 Romney
3/7-3/11/12 1188 RV +/- 3 54 Obama / 42 Romney
4/4-4/15/12 2373 RV +/- 2.3 49 Obama / 45 Romney
5/9-6/3/12 2388 RV +/- 2.3 49 Obama / 42 Romney
6/7-6/17/12 1563 RV +/- 2.9 50 Obama / 46 Romney
6/28-7/9 2373 RV +/- 2.3 50 Obama / 43 Romney
7/16-7/26 1956 RV +/- 3.2 51 Obama / 41 Romney
9/12-9/16 2268 Likely Voters +/-2.4 51 Obama / 41 Romney
10/4-10/7 1112 Likely Voters +/- 3.4 49 Romney / 45 Obama
10/24-10/28 1495 Likely Voters +/- 2.9 47 Romney / 47 Obama
10/31-11/3 2709 Likely Voters +/- 2.2 50 Obama / 47 Romney
So, like most polls, their summer numbers were -6% from the Republican’s final number.
Perhaps it results from the effect of employed people taking vacations. It sure is curious.
Anyway I take it as an historical fact when looking at the current polling and adjust it accordingly for predictive purposes.