The latest Rasmussen Reports national telephone survey found that Senator Barack Obama has opened a ten-percentage point victory over former New York City Mayor Rudy Giuliani, 47% to 37% (crosstabs available for Premium Members). A month ago, they were tied at 43%. The survey also found Obama with a six-point lead over Mitt Romney, 45% to 39%. That’s a slight improvement for Obama who led Romney by four points a month ago.

The numbers for the Obama-Giuliani match-up mark a significant change in the race. Prior to this latest poll, the candidates had been within two points of each other for four straight polls. (see trends and polling history).

The survey was conducted January 2 and 3. All interviews were completed before the results of the Iowa caucuses were known. However, media coverage in the days leading up to the caucus suggested a good showing was likely for Obama. The results in Iowa shook up the race so that there are no national frontrunners on either the Republican or the Democratic side of the aisle.

The Rasmussen Reports daily Presidential Tracking Poll has shown a very close race for months. Heading into the Iowa caucuses, five GOP candidates were within five points of the lead nationally. Among Democrats, Hillary Clinton has consistently been on top in the national polls. It will be interesting to see how these numbers are impacted by the Iowa results in the coming days.

The latest polling shows Obama is now viewed favorably by 50% of Likely Voters nationwide and unfavorably by 46%.

Perceptions of both Giuliani and Romney are sinking. Giuliani now earns positive reviews from 40% of Likely Voters while 57% say the opposite. This represents a stunning turnaround for a man whose favorable ratings topped 70% early in the year.

Thirty-eight percent (38%) of voters have a favorable opinion of Romney, 51% unfavorable.

Crosstabs are available to Premium Members only.

Entering 2008, John McCain was the only Presidential candidate in either party with favorable reviews from more than 50% of voters. McCain and Romney are the top candidates in the upcoming New Hampshire Primary. New polling data on this race will be released throughout the weekend.

Among Democrats, the race in New Hampshire is very close between Obama and Clinton.

In addition to polling services, Rasmussen Reports has launched RasmussenMarkets.com. Market results show that Obama has a % chance of winning the Democratic nomination. Giuliani has a % chance of being the GOP standard bearer, Romney %

These numbers reflect results from a prediction market, not a poll. RasmussenMarkets.com is a “futures market” that harnesses competitive passions to becomes a reliable leading indicator of upcoming events. Using a trading format where traders "buy and sell" candidates, issues, and news features, the markets correctly projected both Obama and Huckabee as the winners in Iowa.

Prospects for other candidates and races are featured on the Rasmussen Markets Summary page. We invite you would to participate in the Rasmussen Markets. It costs nothing to join and add your voice to the collective wisdom of the market.