Here are presidential race results from battleground states polled by Mason-Dixon Polling and Research for MSNBC, Knight Ridder and in Nevada, the Las Vegas Review Journal.
Mason-Dixon Polling & Research, Inc. of Washington, D.C., conducted these polls from Oct. 15-18. A total of 625 likely voters in each state were interviewed by telephone.
Those interviewed were selected by the random variation of the last four digits of telephone numbers. A cross-section of exchanges was utilized in order to ensure an accurate reflection of the state. Quotas were assigned to reflect voter turnout by county.
The margin for error, according to standards customarily used by statisticians, is no more than plus or minus 4 percentage points. This means that there is a 95 percent probability that the "true" figure would fall within that range if the entire population were sampled. The margin for error is higher for any subgroup, such as a gender or regional grouping.