In the 2012 presidential pre-election surveys, Pew Research sampled 1,112 likely voters during October 4–7, 2012, and asked if they were planning to vote for Obama, and then asked the same question of...

In the 2012 presidential pre-election surveys, Pew Research sampled 1,112 likely voters during October 4–7, 2012, and asked if they were planning to vote for Obama, and then asked the same question of a sample of 1,495 likely voters taken from October 24–28, 2012. However, in their last survey taken October 31–November 3, 2012, just before the election held on November 6, 2012, they asked this question of a sample of 2,709 likely voters. Why do you think Pew did this? (Select all that apply.)