PRINCETON, NJ — Voters’ presidential preferences remain favorable to a Barack Obama win on Tuesday, with 51% of traditional likely voters supporting the Democratic nominee for president, and 43% backing John McCain. An additional 1% say they support some other candidate, leaving 5% undecided.

Today’s Gallup Poll Daily tracking results are from interviews conducted nationwide from Thursday through Saturday, Oct. 30-Nov. 1.

The traditional likely voter model producing an eight percentage point lead for Obama takes into account voters’ participation in previous presidential elections as well as their interest in and intention to vote in the 2008 election.

An expanded likely voter model uses only voters’ interest and self-professed likelihood to vote in the current election. On this basis, Obama leads by nine points — 52% to 43% — also with 1% supporting some other candidate and 5% undecided. The expanded model assumes that voter turnout may follow different patterns this year than historically, such as with greater participation by new or infrequent voters.

The expanded likely voter results are not much different from those based on all registered voters. Among the entire sample of eligible voters, Obama leads by 11 points, 52% to 41%. Another 1% name a different candidate while 7% are undecided.

Obama’s lead over McCain among all registered voters has been stable, at or above eight points for each of the past five days. Over the same time period, his lead among traditional likely voters has experienced more variation, highlighting the importance of turnout at this stage of the race in determining whether the election ends up being close, or whether Obama could win by a comfortable margin. — Lydia Saad