By Jason Lange
WASHINGTON (Reuters) - Democratic U.S. Senate candidate Mark Kelly held a big lead over Arizona Republican incumbent Martha McSally on the eve of the election while Republican and Democrat vying for Senate seat in North Carolina were running neck-and-neck, a Reuters/Ipsos poll showed on Monday.
The outcome of about 14 of 35 U.S. Senate races is anyone's guess in Tuesday's election, 12 with vulnerable Republican incumbents and two with vulnerable Democrats. To have a majority in the Senate, Democrats need to pick up three seats if they also win the White House, which gives the vice president a tie-breaking vote, and four if not.
Here are the latest results for three Senate races on which Reuters/Ipsos is polling:
ARIZONA (Oct. 27 - Nov. 1 poll)
* Voting for Democratic challenger and former astronaut Mark Kelly: 53%
* Voting for Republican Senator Martha McSally: 44%
* A prior poll showed Kelly leading McSally 51% to 44%.
* 49% said they had already voted.
NORTH CAROLINA (Oct. 27 - Nov. 1 poll)
* Voting for Democratic challenger Cal Cunningham: 48%
* Voting for Republican Senator Thom Tillis: 46%
* The race is statistically tied because the difference between the two is within the survey's credibility interval, as it was the prior week when Cunningham had 48% to Tillis' 47%.
* 43% said they had already voted.
MICHIGAN (Oct. 21-27 poll)
* Voting for Democratic Senator Gary Peters: 51%
* Voting for Republican challenger John James: 44%
* Peters led James 50%-44% in the prior week.
* 37% of adults said they had already voted.
NOTES: The Reuters/Ipsos poll was conducted online and in English. The Arizona survey included 610 likely voters and had a credibility interval of 5 percentage points. North Carolina's surveyed 707 likely voters and had a credibility interval of 4 percentage points. The earlier Michigan poll surveyed 654 likely voters and had a credibility interval of 4 percentage points.