ST. PAUL, Minn. -- The days when a presidential nominee picked a running mate to deliver votes in key battleground states are rapidly diminishing, some scholars and pundits say, adding that while history suggests running mates don’t change general election outcomes, this year's crop is drawing intense interest and the outcome may be different.

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University of St. Louis professor Joel Goldstein, author of "The Modern American Vice Presidency," said running mate selections have instead become topics of national interest and consequence owing to an age in which the Internet and 24-hour news cycles cast a far more intense spotlight than they used to. And once their ticket wins the White House, the stage has been set for vice presidents to play far more influential and powerful roles than in times past.

He said he was stunned by Republican nominee Sen. John McCain's pick of Alaska Gov. Sarah Palin, but better understood Democratic nominee Sen. Barack Obama giving the nod to Delaware Sen. Joe Biden.

Since Obama is relatively new to the national stage and McCain just turned 72 and has previously dealt with bouts of skin cancer, Goldstein had predicted before they made their choices, they would choose partners who themselves might be worthy presidents.

The selection would also be the first major decision they would make in front of a national audience: "Do they see this as someone who could sit in the Oval Office?" Goldstein said. And, "Is this how you size up talent?"

In his view, Palin "doesn't pass the straight-face test" as someone with presidential credibility, Goldstein said. "I can't recall in modern times a presidential or vice presidential candidate where service as the mayor of a small town has been passed off as relevant experience" for a person who might quickly be called upon to occupy the Oval Office.

Vice President Dick Cheney, for example, began his public service as a congressional intern in 1969. He served in a variety of Nixon and Ford administration staff positions, served six terms in the House representing Wyoming, was Secretary of Defense under President George H.W. Bush and directed Operation Desert Storm and was CEO of Halliburton before being named as George W. Bush's running mate -- and elected as vice president -- in 2000.

Palin, by contrast, served on the Wasilla, Alaska, City Council from 1992-1996, and was then mayor of Wasilla from 1996-2002. (The town, with a population estimated at 9,780 by the U.S. Census in 2007, is about an hour's drive north of Anchorage.) She launched a failed bid for lieutenant governor of Alaska in 2002. And she was the ethics supervisor of the Alaska Oil and Gas Conservation Commission from 2003-2004, before being elected governor in the fall of 2006.

But Palin has shaken up the race.

Norman Ornstein, of the American Enterprise Institute, said in a symposium during the Republican National Convention in St. Paul that McCain's selection of Palin showed McCain was willing to take a gamble that might change the face of the race over the long haul – depending on how Palin stands up to the pressure of the race.

"The choice of Palin was the fighter-pilot (in) John McCain," Ornstein said. "It was impulsive, shoot-from-the-hip, take-a-risk, and hope that it pays off."

Vin Weber, a long-time Republican activist and former GOP congressman, speaking at the same event as Ornstein, said he "really didn't expect" the Palin pick because she "didn't meet the basic qualifications" for the office. But he said that between her introduction in Dayton, Ohio, before the convention, and the wild enthusiasm expressed for her by the delegates, "I think she can be a great asset."

At least in the short term, Palin has turned out to be an enormous boon to McCain on the campaign trail. She electrified the Republican National Convention. Since then she and McCain have been greeted with large, enthusiastic crowds almost everywhere they have campaigned. And her presence on the ticket is credited with giving McCain a strong post-convention bounce in opinion polls. One, by USA Today-Gallup published on Sept. 8, put McCain ahead of Obama for the first time, by 50-46 percent. (See Polls)

Goldstein said Biden's nomination made more sense to him – a safe choice. The senator has run for the White House himself. He has spent 23 years in the Senate representing Delaware and has played key roles in a long list of legislative initiatives on both the domestic and international stages. His experience brings with it relationships on Capitol Hill that can help advance a president's legislative agenda. And his experience also helps Obama with voters because it bolsters his own, shorter resume, especially in international affairs.

Obama said as much recently, when he was asked about Biden by "Late Show" host David Letterman.

"You know, the way I thought about it was, 'Who’s going to help me govern? Who's the person I want in the room if we've got a big decision to make?" Obama said. "Who's going to be able to give me good counsel, good advice? Who's able to maybe have some ideas that I don't have or give me a perspective that I haven't seen. I think that nobody can do that better than Joe Biden."

But campaigning matters too. Biden was also chosen for the possibility that he could help Obama earn the votes of white, working-class voters who supported Sen. Hillary Rodham Clinton, Goldstein said. He has a "regular guy" biography with working-class appeal, combined with a life-begins-at-conception brand of Catholicism that may resonate in battleground states like Pennsylvania, Ohio and Michigan.

So far, Palin has grabbed such intense media interest that Biden has been somewhat obscured, even has he has kept up a steady schedule of campaign events. Voters will see them together for the first time when they meet for a debate at Washington University in St. Louis, Mo., on Oct. 2.

Will Palin or Biden change the course of the election? Ornstein and Weber said history suggested not, but they agreed that Palin added a note of less certainty to what both men described as a gloomy year for the GOP.

Citing John Petrocik of the University of Missouri, Republican strategist Karl Rove recently wrote in the Wall Street journal that from 1972-2004, running mates had an impact of less than 1 percent on the outcome. But, while running mates usually don't matter, "this may be an unusual election."

While running mates serve as useful surrogates to the presidential nominees during the campaign, they may also, if elected, be a heartbeat away from the presidency. A vice president's succession to the Oval Office is not unusual in the country's history. Since George Washington, nine vice presidents have taken over as president.

There is no official constitutional duty for the vice president -- the common role has been to shepherd the president's legislative agenda through Capitol Hill and function as a stand-in for the president in official capacities at home and abroad. John Nance Garner, Franklin Roosevelt's vice president, once famously described it as being "not worth a bucket of warm (spit)."

Times have changed, however. Democrat Walter Mondale broke new ground in the office serving under President Jimmy Carter: Their staffs were combined, and there were "no secrets" between the two, he told an audience at the University of Minnesota in May. That kind of access was key to what Mondale said was a need for the president to have a trusted adviser.

In a now-famous memorandum to Carter before he was inaugurated in 1976, Mondale wrote, "The biggest single problem of our recent administrations has been the failure of the president to be exposed to independent analysis not conditioned by what it is thought he wants to hear or often what others want him to hear. I hope to offer impartial advice and help assure that you are not shielded from points of view that you should hear." (Download Document)

More recently, Al Gore used his vice presidency to advance environmental issues and an initiative to use the Internet as a tool for making the federal bureaucracy more transparent. And Dick Cheney has used his position to advance what he has told author Bob Woodward is "a restoration, if you will, of the power and authority of the president."

Palin's resume led Goldstein to doubt her potential effectiveness as a legislative liaison between the White House and Capitol Hill. Unlike Biden, with his decades of networks and relationships, she's unknown. But, should the McCain-Palin ticket win, he said it's possible she might function as an aggressive spokesman for the president's agenda -- more in the mold of Spiro Agnew's role in the Nixon White House -- and serving as a conduit to the party faithful whom she helped draw to the polls.