The Gallup Organization, in a survey Friday, also reveals Palin has low name recognition, with a majority of those polled saying they had never heard of her.
Only 39 percent said they believe Palin is qualified to serve as president, while 33 percent said she is unqualified and 29 percent were not sure. When Democratic nominee Barack Obama picked U.S. Sen. Joseph Biden of Delaware last week, 57 percent said Biden could step into the top job.
Sen. John McCain, the Republican presidential nominee, announced his selection of Palin at a rally in Dayton, Ohio, Friday. It was Palin's first real national appearance after two years as governor and several as mayor of Wasilla, a town of 8,000.
A majority of respondents said the vice presidential pick would not affect their vote, with 67 percent saying that of Palin and 72 percent of Biden. While 18 percent said the Palin choice makes them more likely to vote for McCain, 11 percent said they were less likely. Similar numbers for Biden were 14 percent and 7 percent.
Gallup polled 898 people by telephone. The poll has a margin of error of 4 percent either way.