By Andy Sullivan
WASHINGTON, Oct 23 (Reuters) - President Barack Obama pulled slightly ahead of Republican Mitt Romney in a Reuters/Ipsos daily tracking poll on Tuesday, but the race remained essentially tied with two weeks to go until the Nov. 6 election.
Obama led Romney among likely voters by a statistically insignificant margin of 1 percentage point, 47 percent to 46 percent. The four-day online tracking poll includes some responses taken after the two candidates' final televised debate, but the full impact will not register for several days.
Obama maintains a larger advantage in the state-by-state battle that will determine the outcome of the election. Ipsos projects that Obama holds an edge in the most hotly contested states, including Florida, Virginia and Ohio, and is likely to win by a relatively comfortable margin of 322 electoral votes to 206 electoral votes.
The poll has reflected a tight race since shortly after the two candidates met for their first debate on Oct. 3. But a substantial portion of voters remain up for grabs. Roughly 20 percent of those surveyed say they could switch their votes or have not yet made up their minds.
Among the larger pool of registered voters, Obama leads Romney 46 percent to 42 percent.
The accuracy of Reuters/Ipsos online polls are measured using a credibility interval. The survey of 1,030 likely voters has a credibility interval of 3.5 percentage points. (Editing by Alistair Bell and Stacey Joyce)