GOP presidential candidate Mitt Romney is holding steady with a 6-point lead over President Obama, according to Monday’s Gallup daily tracking poll.

Romney takes 51 percent support over Obama at 45 in the survey of likely voters. Among registered voters, Romney’s lead is 48 to 47 over the president.

The survey is a rolling seven-day average through Oct. 21, so it includes five days of polling data since the second presidential debate last Tuesday night in Hempstead, N.Y.

Monday marks the sixth consecutive day Romney has held at least a 6-point advantage over Obama. During two of those days he led by 7 in the Gallup tracking poll.

According to the RealClearPolitics average of polls, Romney is at 47.4 percent support and Obama at 46.7.  In addition to including Gallup’s 6-point lead for Romney, that average includes an IBD-TIPP poll that shows Obama up by 6. 

But many believe the race is much closer nationally than the Gallup daily tracking poll suggests. According to an NBC News/Wall Street Journal poll released Sunday, the candidates are knotted at 47 percent each among likely voters.

A Reuters-Ipsos poll released just moments after Gallup’s daily tracking survey on Monday also shows the candidates tied, with each receiving 46 percent support. And the tracking poll from conservative-leaning Rasmussen shows a two-point spread, with Romney topping Obama 49 to 47.

The race appears similarly close in the dozen or so battleground states that will determine who wins more Electoral College votes, and ultimately, the election.

Republicans are optimistic that they are in control of three key southern swing states — North Carolina, Virginia and Florida — although polls in the latter two remain tight.

A Rasmussen poll puts Romney up 5 in Florida at 51-46, but two other surveys give him a narrower lead, with Fox News putting Romney up 48-45 and a survey from Democratic-affiliated Public Policy Polling (PPP) pegging Romney up 1 at 48-47.

In Virginia, Rasmussen shows Romney up 3, with an ARG poll putting the GOP nominee up 1.

Democrats, meanwhile, are confident Obama will hold on to Michigan, Pennsylvania and Wisconsin.

That leaves Iowa, Nevada, New Hampshire, Colorado and Ohio — all of which are presently toss-ups. The Buckeye State is by far the biggest electoral prize of the remaining states, and whoever wins there, will likely win the election.

Obama has led in Ohio throughout this cycle, and a Quinnipiac-CBS News poll released Monday shows the president ahead by 5. But a PPP survey puts Obama up 1, with Suffolk finding the presidential contenders in a dead heat. The RCP average of polls shows Obama only up by 1.9 percentage points in the battleground state.

The Gallup daily tracking poll has a margin of error of 2 percentage points.

This story was updated at 1:40 p.m.