(CNN) - With four days to go until the midterm elections, a second straight poll in the most high profile Senate battle in the country indicates Republican challenger Sharron Angle holds a four point advantage over Senate Majority Leader Harry Reid.
But Angle's four point margin in a new Mason-Dixon survey for the Las Vegas Review-Journal/8 News Now is within the poll's sampling error, making it a neck and neck race.
According to poll, 45 percent of likely voters in Nevada are backing Angle, who enjoys strong support from many in the Tea Party movement, with 45 percent backing Reid, the top Democrat in the Senate, who's bidding for a fifth term in the chamber.
Three percent of people questioned in the survey say they are undecided, with one percent saying they are backing other candidates on the ballot and two percent saying they will vote for none of the candidates, which is a ballot option in Nevada.
The Mason-Dixon poll's Friday release comes two days after a CNN/Time/Opinion Research survey indicated that Angle held the same 49 to 45 percent advantage over Reid. Two percent questioned in the CNN/Time poll supported Scott Ashjian, who is running as a Tea Party candidate, but who is shunned by many in the grassroots conservative movement, and three percent saying they are voting for none of the candidates listed. Angle's margin in the CNN poll is within that survey's sampling error.
Other surveys released in the past two weeks also indicate a small single digit margin for Angle.
According to the Mason-Dixon survey, Angle leads 85 to 8 percent among Republicans and 55 to 38 percent among independent voters, with Reid ahead 84 to 11 percent among Democrats.
"Reid just can't get much above 45 percent, and she's carrying the independents," Mason-Dixon pollster Brad Coker tells the Review-Journal. "I haven't seen a poll showing him up since the debate. That might have been when things started to lock in."
Reid and Angle faced off October 14 in their only debate.
According to the CNN/Time poll, Reid leads 96 to 3 percent among Democrats, with Angle leading 82 to 10 percent among Republicans and 53 to 38 percent among independent voters.
"Reid is doing best in Clark County, home not just to Las Vegas but to his hometown of Searchlight," says CNN Polling Director Keating Holland. "He manages a virtual tie with Angle in her home territory in Washoe County, where Reno is located. But Reid is getting clobbered in the rest of the state, losing the rural areas of Nevada by more than three-to-one."
In a sign that enthusiasm for voting appears to be on the Republican side, when expanded from those likely to vote to the larger sample of all registered voters, Reid holds a 43 to 39 percent advantage over Angle, with five percent backing Ashjian and 12 percent saying they'll vote for none of the candidates.
President Barack Obama teamed up with Reid in Nevada last week. According to the poll, 39 percent of likely voters in Nevada approve of the job Obama's doing as president, with 59 percent saying they disapprove. Among all adults in the state, 44 percent approve of the job Obama's doing, with 49 percent disapproving of how he's handling his duties.
The Mason-Dixon poll indicates that 39 percent have a favorable opinion of Reid, with 56 percent saying they hold an unfavorable opinion. Likely voters are split on Angle, with 43 percent saying they have a favorable opinion of the former state lawmaker, with 45 percent saying they see her in an unfavorable light.
The survey's sampling error is plus or minus four percentage points.
The Mason-Dixon poll was conducted October 25-27, with 625 likely voters in Nevada questioned by telephone. The survey's sampling error is plus or minus four percentage points.
The CNN/Time/Opinion Research Corporation poll was conducted October 20-26, with 1,504 Nevada adults, including 1,286 registered voters and 773 likely voters questioned by telephone. The survey's overall sampling error is plus or minus 2.5 percentage points, with a sampling error of plus or minus 3.5 percentage points for likely voters.