CNN Poll of Polls: Ohio a close contest on eve of election

(CNN) -- A new CNN Poll of Polls on Monday indicates the race in Ohio--perhaps the most decisive battleground this presidential cycle--is locked in a statistical dead heat.

The poll shows President Barack Obama at 50% and Mitt Romney at 47% in Ohio, one day before the election. Those numbers are an average of three Ohio polls of likely voters conducted in the last week: Ohio Poll/University of Cincinnati (Oct. 31-Nov. 4); CNN/ORC International (Oct. 30-Nov. 1) and NBC/Wall Street Journal/Marist (Oct. 31-Nov.1). The Poll of Polls does not have a sampling error.

Both campaigns have been barnstorming Ohio, which has 18 electoral votes, in recent days, as many political observers consider the state a must-win for an overall victory on Tuesday. Obama, Romney and Romney's running mate, Rep. Paul Ryan, will each appear in the Buckeye State to make their pitch on Monday.

The latest Ohio survey, from the University of Cincinnati, has the closest margin of the three polls, with 50% of likely voters in the state supporting Obama, while 49% back Romney. The one-point margin falls well within the sampling error of plus or minus 3.3 percentage points, leaving the two candidates statistically tied. The university interviewed 901 likely voters by telephone.

The new Ohio poll comes a few days after the CNN/ORC International poll, which had Obama at 50% and Romney at 47%, mirroring Monday's Poll of Polls.

The University of Cincinnati poll--its final survey of the cycle--also gave numbers on the tight U.S. Senate race in the state, showing incumbent Sen. Sherrod Brown, a Democrat, at 51%, while his Republican challenger Josh Mandel, the state treasurer, comes in at 47%.