Thirty-eight percent (38%) of U.S. voters are very concerned that Barack Obama will be tested with an international crisis in his first six months as president, as his running mate Joseph Biden has predicted.

Another 21% rank themselves somewhat concerned about such a crisis, while just 12% are not concerned at all, according to a new Rasmussen Reports national telephone survey.

Forty-three percent (43%) of male voters are very concerned that Obama will be tested in his first six months, compared to 33% of women. Sixty-seven percent (67%) of Republicans have that level of concern, versus 15% of Democrats and 36% of unaffiliated voters (see full demographic crosstabs).

Voters are evenly divided over which candidate, if elected, would best handle an international crisis early in his presidency. Forty-nine percent (49%)have more confidence in John McCain; 48% in Obama. Men have more confidence in McCain by eight points, women more confidence in Obama by five.

Forty-eight percent (48%) of voters say Obama’s inexperience is a bigger risk than McCain’s age in the event of such a crisis. However, 44% believe just the opposite. While 53% of men are more worried about the Democrat’s lack of experience, a plurality of women voters (47%) say McCain’s age is a bigger concern.

The closeness of these numbers are cold comfort to the McCain campaign since voters consistently have trusted McCain more than Obama in the area of national security. In the most recent survey, the Republican had a seven-point edge.

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Obama has enjoyed a modest lead over McCain every day for nearly a month in the Rasmussen Reports daily Presidential Tracking Poll.

"Mark my words," Biden said in a speech over the weekend. "It will not be six months before the world tests Barack Obama like they did John Kennedy. The world is looking."

McCain’s campaign seized on the comments to raise concerns that Obama is not ready to be president.

Obama dismissed Biden’s comments, saying his running mate was prone to “rhetorical flourishes,” but held a high-profile meeting with his national security advisers on Wednesday in part to allay voter concerns raised by the comments.

Fifty-six percent (56%) of voters now have a favorable opinion of Biden, and 41% regard him unfavorably. These numbers are identical to the findings in a survey two weeks ago which found Biden, a 35-year member of the Senate, is now viewed more positively than Republican vice presidential candidate Sarah Palin.

Opponents of the Republican ticket have questioned whether the 44-year-old Palin, a first-term governor of Alaska, is ready to be president should anything happen to McCain, who is 72. Republicans have countered that Obama, a first-term U.S. senator who previously served in the Illinois Senate, also lacks significant experience, and the naming of Biden to the number two slot was viewed as response to that concern.

Sixty-seven percent (67%) percent say they have followed news stories about Biden’s comments at least somewhat closely, including 38% who have followed them very closely. Only 10% say they have not followed the stories at all.

Fifty-seven percent (57%) of those who have followed the stories very closely are very concerned that Obama will be tested with an international crisis in his first six months as president. Sixty-four percent (64%) have more confidence in McCain to handle it, compared to 36% who say that of Obama.

In this group, 64% say Obama’s inexperience is a bigger risk than McCain’s age, but 32% see the GOP candidate’s age as a greater concern.

Fifty-one percent (51%) of investors consider Obama’s inexperience a bigger risk in the event of a crisis than McCain’s age, compared to 41% of non-investors. Similarly, 52% of investors have more confidence in McCain to handle a crisis in the first six months of his presidency versus 40% of non-investors.

New presidential polling data also has been released this week from Colorado, Florida, Kentucky, Missouri, North Carolina, Ohio, South Carolina, Tennessee, Texas, Virginia and West Virginia. See an overview of all state polls and the latest Electoral College projections. A total of 270 Electoral Votes are needed to win the White House (see 50-State Summary).

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