A Mobile Press Register/University of South Alabama poll in Mississippi shows Republicans John McCain in the presidential race and Roger Wicker in a U.S. Senate contest hold sizable percentage leads over their opponents heading into the final days of the campaign.

The telephone survey of 405 registered, likely Mississippi voters was conducted between Oct. 13 and Thursday by the USA Polling Group. It has a margin of error of plus or minus 5 percentage points.

The poll found that in the presidential contest, McCain is leading Democrat Barack Obama by a 46 to 33 percent margin, while it found Wicker, the incumbent senator, has 45 percent of the vote, compared to 32 percent for Democrat Ronnie Musgrove.

Other surveys have indicated a much tighter Senate race, and one outside observer questioned the findings because about one-third of black respondents said they were undecided, declined to answer or said they are voting for someone else.

David Bositis of the Joint Center for Political and Economic Studies says the vast majority of black Mississippi voters will support Obama and Musgrove in the Nov. 4 general election.

Bositis, senior political analyst for the Washington-based think tank that focuses on black issues, also said that factoring in those votes would mean both races become “too close to call.”

The poll is the first that the Press-Register in Mobile has conducted in Mississippi. It comes as the newspaper publishes a new Mississippi edition for the state’s southeast corner.

Adam Bozzi, a Musgrove campaign spokesman, said the Press-Register findings do not reflect the results of both internal campaign and public polls showing the contest to be within a percentage point or two in either direction.

And Wicker campaign spokesman Ryan Annison, told the newspaper, “There will be lots of polls between now and Nov. 4. … We are confident Senator Wicker will win.”

The newspaper said that in both Mississippi contests, more than one out of five respondents overall said they are undecided, favor other candidates, or would not answer. USA Polling Group Director Keith Nicholls attributed that relatively high percentage in part to ambivalence about the candidates.

Nicholls acknowledged some puzzlement on his part that about one out three black respondents fell in that category. Obama’s status as the first black candidate ever to head a major-party ticket is expected to generate heavy black turnout on his behalf around the country.