Voters are mixed on Obama: 39 percent rate him favorably, 41 percent rate him unfavorably and 19 percent say they are neutral. Romney, on the other hand, has a more positive image rating: 36 percent of likely voters have a favorable opinion of him, while only 29 percent have an unfavorable opinion and 31 percent say they feel neutral. Meanwhile, as in other public polls, the Senate race is a tie. Allen and Kaine each take 46 percent of the vote, according to the poll, with 8 percent undecided. Kaine, the former chairman of the Democratic National Committee, wins 90 percent of Democrats. Allen, who also served as the commonwealth's governor, earns 91 percent of Republicans. By a slight, six-point margin, independents lean toward Kaine. Virginia voters have good impressions of both candidates: 41 percent say they have a favorable opinion of Allen, while 39 percent have a favorable opinion of Kaine. But the percentages of voters having unfavorable impressions of each candidate is 18 percentage points fewer than their respective favorability ratings. The final political question added to the survey by Mason-Dixon asked about Republican Gov. Bob McDonnell's job performance. A majority of likely voters, 63 percent, rate McDonnell's performance as either "excellent" or "pretty good," while only 30 percent think he is doing an "only fair" or "poor" job. Governors of Virginia may only serve one term, but McDonnell, who last week endorsed Romney for the GOP presidential nomination, is a likely bet to be on his party's vice-presidential shortlist this summer. The Mason-Dixon poll was conducted Jan. 16-18, surveying 625 likely voters in the state.