WASHINGTON — Just four in 10 say Republican vice presidential nominee Sarah Palin has enough experience to be president, while nearly two-thirds say so about Joe Biden, her Democratic counterpart, a poll showed Friday.

Views of Palin largely reflect partisan loyalty and show she's having little initial impact on which presidential ticket people support, the ABC News survey showed.

Eight in 10 Republicans and more than four in 10 independents say they have more confidence in Republican presidential nominee John McCain's decision-making for his selection of Palin. Six in 10 Democrats say it reduces theirs. More have a favorable than unfavorable view of Palin by 50 percent to 37 percent — a bit less than the 54 percent to 30 percent positive opinion they have of Biden.

Palin is seen favorably by 85 percent of Republicans, 24 percent of Democrats and 53 percent of independents.

By just 6 percentage points, people say her choice makes them likelier to vote for than against the McCain ticket. Pivotal GOP voting blocs — conservatives, Republicans and white evangelicals — are all likelier to support than oppose McCain because of Palin by 32 points or more.

Biden makes people likelier to support Democratic presidential nominee Barack Obama by 12 points. Most say neither vice presidential pick will make a difference.

Seven in 10 say the pregnancy of Palin's unmarried teenage daughter doesn't affect their view of Palin. By 2-to-1 most say the mother of five — including an infant with Down syndrome — made the right choice to become McCain's running mate.

Women and men back Palin's choice to run about equally. Republicans and independents are far likelier than Democrats to support her decision.

Four in 10 say Palin's choice to have her youngest child after a diagnosis of Down syndrome makes them feel more favorably about her, while just over half say it had no impact.

The poll was conducted Thursday and involved telephone interviews with 505 adults. It had a margin of sampling error of plus or minus 4.5 percentage points.