The numbers

Via Gallup:

Forty-three percent of voters say Barack Obama's economic and tax plans make them more likely to vote for him, compared with 30% who say this about John McCain and his plans. In fact, more voters say McCain's plan for the economy and taxes makes them less likely to vote for him.

In its Oct. 3-5 poll, Gallup asked a random sample of registered voters nationwide whether each of eight factors -- spanning many of the candidates' important policy differences and background characteristics -- made them more likely or less likely to vote for Obama, or made no difference to their vote. The same eight factors were asked separately in regard to McCain.

Most voters say the candidates' past positions on the Iraq war will influence their vote. In general, voters tend to view Obama's past Iraq war opposition as a plus -- 43% say it makes them more likely to vote for him, tying his economic plan as the voting factor making the biggest positive contribution to the Obama candidacy. With this positive endorsement of Obama's war opposition, it is thus not surprising that McCain's support for the decision to go to war in 2003 is viewed as more of a drawback in voters' minds.

However, the candidates' differing positions on the U.S. troop surge in Iraq work to McCain's benefit. Thirty-eight percent say McCain's support of the 2007 troop surge makes them more likely to vote for him; only 32% cite Obama's opposition to the surge as something that increases their likelihood of voting for him.

In fact, this is the only one of the eight items tested in the poll that appears to be a disadvantage for Obama. On the seven others, more voters say it makes them more likely to vote for the Democratic nominee than say it makes them less likely to do so. This could largely reflect Obama's leading position in the polls at this stage of the campaign.

Race and Age

Both candidates would make history if elected in November, with Obama seeking to become the first black president and McCain the oldest elected to a first term. Voters may not necessarily consider either factor a plus -- lingering racism could cause some voters to cast a ballot against Obama solely on the basis of his race, and some voters may be uncomfortable electing a president as old as McCain to such a demanding job.

The poll finds that age appears to be a much more relevant factor in the vote this year than is race -- at least based on these self-reports.

Relatively few voters say race will be a factor in their vote -- at least 85% say it will make no difference in their decision to support either candidate. The impact of Obama's race has been the focus of much discussion in this campaign. According to what voters say in this poll, his race is actually a net plus. Of the small number of voters who say Obama's race will affect their vote, a slightly higher percentage say his race will make them more likely (9%) rather than less likely (6%) to vote for him. Interestingly, these responses are not significantly different from the percentages who say McCain's race will affect their vote.

Voters are somewhat more likely to factor the candidates' ages into their voting calculus, but in each case a majority say this will not affect their vote (although fewer say it makes no difference in their decision to vote for McCain than in their decision to vote for Obama).

On balance, age is clearly a negative factor for McCain, and a positive one for Obama. Thirty-eight percent of voters say McCain's age makes them less likely to vote for him; only 7% say it makes them more likely. Meanwhile, 24% say Obama's age increases their odds of voting for him, while 9% say it decreases those odds.

That more negative assessment of McCain's age is in large part because of the opinions of Democrats -- a majority of whom say it makes them less likely to support the GOP nominee. Most independents and Republicans say his age makes no difference to their vote.

The Running Mates

The poll suggests that, overall, Joe Biden does more to help the Democratic ticket than Sarah Palin does the Republican ticket. Thirty-seven percent of voters say Obama's selection of Biden as his vice-presidential running mate makes them more likely to vote for the Democratic candidate, compared with 19% who say it makes them less likely to do so. By 41% to 33%, voters say McCain's choice of Palin makes them less likely to vote for the Republicans in November.

Even so, Palin appears to be doing more to fire up her party's natural supporters than Biden is doing to motivate the Democratic base. Sixty-five percent of Republicans say Palin's presence on the ticket makes them more likely to vote for McCain, compared with 57% of Democrats who say Obama's choice of Biden makes them more likely to vote for Obama.

Survey Methods

Results are based on telephone interviews with 926 registered voters, aged 18 and older, conducted Oct. 3-5, 2008. For results based on the total sample of national adults, one can say with 95% confidence that the maximum margin of sampling error is ±4 percentage points.

Interviews are conducted with respondents on land-line telephones (for respondents with a land-line telephone) and cellular phones (for respondents who are cell-phone only).

In addition to sampling error, question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of public opinion polls.