It’s accepted wisdom in presidential politics that national polling on a primary race is largely meaningless since the nominees of both parties are typically picked in the crucible of the Iowa caucuses and New Hampshire primary.

In this Oct. 18, 2011, file photo, Republican presidential candidates Herman Cain, left, former Massachusetts Gov. Mitt Romney, center, and Texas Gov. Rick Perry are seen before a Republican presidential debate in Las Vegas. (AP Photo/Isaac Brekken, File)

“It feels like everything got off to a late start and there’s been a lot less retail in the early states,” said Mark Salter, the lead political strategist for Arizona Sen. John McCain’s 2008 presidential campaign.

Take Iowa. Thanks to the Post’s brand new primary tracker — bookmark it! — we can quickly see that businessman Herman Cain has visited the state 28 times since June 2011 while former Massachusetts governor Mitt Romney has been in the state just nine times in that same time period. In the last 30 days, Romney has been in Iowa six times while Cain has stopped in just a single time.

The same phenomenon is playing out in New Hampshire. While Romney is the favorite in the state — thanks to his geographic appeal as a former Massachusetts governor — Cain has vaulted into a second place in recent polls despite having only visited the Granite State ten times since last June.

What those numbers suggest is that the traditional blueprint of success — lavish time (and money) on places like Iowa and New Hampshire in order to win over those voters which in turn makes you viable everywhere else — simply isn’t operational this time around.

The driving force in the race to date appears to be some combination of debate performances and way in which the national media has covered the race.

What else explains the rapid rise of Texas Gov. Rick Perry in both state and national polls followed by his equally rapid fall in the wake of a series of shaky debate performances?

Or Cain’s surge from an asterisk to a frontrunner despite the fact that he has been in the two earliest voting states a total of one time in the past 30 days and hasn’t spent a dime on television advertising in either?

The current dominance of the national narrative is also closely tied to the fact that a) the race remains almost entirely disengaged in early states and b) none of the candidates trying to emerge as the anti-Romney are at all well known.

Prior to Perry launching ads in Iowa last week (and New Hampshire this week), the only candidate who had done any major advertising in either state was Rep. Ron Paul who, as we have written before, has a very loyal core of support but little demonstrated capacity to expand it.

Combine that lack of spending with the fact that most of the candidates aren’t well known figures nationally and the reality is that the race really hasn’t touched voters in Iowa and New Hampshire on any sort of personal level.

“This is the first time we’ve had a primary where most conservative candidates are unknown,” said Jan van Lohuizen who handled polling for President Bush’s 2004 campaign. “We don’t have an ‘old familiar’ with good credentials running, and that has not happened in while.”

What that means is that the national media coverage of the race is of outsized importance.

The coverage of Bachmann’s rise following her first debate — early June in New Hampshire — fueled her ascent. Ditto Perry in the wake of his entrance into the race in mid-August. And Cain, after he won the Florida P5 straw poll and strung several solid debate performances together. (Following that trend, former House Speaker Newt Gingrich may well be the next “conservative alternative” as he has been getting some nice press of late.)

The question is whether the national domination of the campaign narrative will continue. Through the early fall of 2008, there were still plenty of stories pointing out then Sen. Hillary Clinton’s wide lead in national Democratic primary polling against then Illinois Sen. Barack Obama. And we all know how that one turned out.

But, there are no Clintons or Obamas — major national figures with tens of millions in the bank — in the 2012 Republican presidential race.

And that means it’s uniquely possible that the current trend will continue — with the national conversation dictating the political realities on the ground in Iowa and New Hampshire.