A recent poll conducted by NBC News/Survey Monkey shows that a majority of Americans don't know enough about vice presidential candidates Mike Pence or Tim Kaine to form a positive or negative impression of them. Voters didn't know as much about Virginia Sen. Tim Kaine (40 percent) than they did of Indiana Gov. Mike Pence (33 percent). The poll was conducted online from September 26 through October 2 among likely voters. Both Kaine and Pence go head-to-head tonight in Tuesday's debate at Longwood University in Farmville, Virginia.