Normally, I'm not a big fan of national polling in a primary season.  A candidate's success is typically dependent on the momentum they get from one regional contest to the next, not on the general mood of the national public towards them.  Remember those hilarious national polls in 2003 showing Joe Lieberman running away with it?

However, as we get closer to February 5th's "Super Tuesday" contest, with 22 states holding primaries, a national poll would appear to have more relevance.  Today's Reuters/Zogby nationwide poll shows the first-ever dead heat of the Democratic contest:

Barack Obama has erased a once substantial deficit to climb into a virtual tie with Hillary Clinton in the Democratic presidential race, according to a Reuters/Zogby poll released on Wednesday.

Clinton, a former first lady who would be the first woman U.S. president, held a 21-point edge over Obama in October.  He cut that to 8 points by last month, and the new survey gave her a 39 percent to 38 percent edge.

Her 1-point lead was well within the poll's margin of error of 4.7 percentage points.

Obama, who would be the first black U.S. president, and Clinton were essentially deadlocked among a variety of groups, including men, women, Democrats and independents.  Obama led substantially, 65 percent to 15 percent, among black voters.

Obama barely led among voters under age 24, a substantial drop in support from last month, but led Clinton among voters aged 55 to 69, normally one of her strengths.