In Arizona, Biden polled ahead of Trump, 50 to 46 percent, which is in line with recent public polling, but the results are within the 4.1-point margin of sampling error.
Biden narrowly leads Trump in North Carolina, 51 to 45 percent. Recent public polling in North Carolina has shown a tighter race in the state, but an NBC News/Marist poll released Friday showed a 6-point lead for the former vice president.
Trump won all four states in 2016, and the results in each could prove critical to determining a winner in Tuesday’s election. Both Trump and Biden have made stops across the Midwestern states over the past week.
The respective telephone polls were conducted by research firm SSRS from Oct. 23 to Oct. 30, with a sample size of over 1,000 for each.