GILBERT, Ariz. -- Four years ago, before a little-known governor from Alaska stepped onto the American political stage, Lisa Rigler was a steadfast John McCain supporter. She was a Republican and an Arizonan, so it was a given that she would back the state's senior senator in his bid to become president.
Then McCain introduced his running mate, promising that his pick would help him "shake up" Washington. Sarah Palin would, instead, shake up his campaign and the political landscape of the nation.
But was her selection the "game-changer" so many Americans believed it to be? Does that No. 2 spot on a presidential ticket make any real difference to voters in the long run?
It's that second question that Rigler and others are asking again, now that Mitt Romney, the likely Republican presidential nominee, has made his own big announcement, selecting Rep. Paul Ryan of Wisconsin as his candidate for vice president.
"It always matters," said Rigler, recalling what happened in the post-Palin, pre-election interval, when she started hearing from friends and fellow Republicans in Arizona who planned to abandon the state's favorite son because of his "horrible" choice. Rigler herself went from intrigued to annoyed as she witnessed what she called McCain's "total snowball downhill."
In the end she stuck with McCain. But as a Romney supporter, Rigler had three words of advice for her man this go-around: "Choose really wisely."
On Saturday, Romney did choose -- and with the pick came the predictable speculation: Would Ryan help rally conservatives or perhaps turn off independents? Would he solidify Romney's economic message or fuel characterizations that those ideas are too radical? Might he potentially swing Wisconsin to the Republicans or re-energize the opposition there?
In short: Will he, in the end, change the election's outcome?
Four years after Palin, it might certainly feel to voters as though the choice of a ticket's No. 2 can be a make-or-break decision for the ticket's No. 1. A recent New York Times/CBS News poll found that 26 percent of voters think the vice presidential candidate "matters a lot," while 48 percent said it matters somewhat. An additional 25 percent said it didn't affect their vote at all.
But experts note that the pick actually doesn't do much, if anything, to change the final result.
"There's not a ton of research on this, but there's enough so that we can say fairly definitively: The choice of a running mate doesn't help or hurt the vote in November for a particular presidential candidate," said Jody Baumgartner, a political science professor at East Carolina University in Greenville, N.C., and author of the book "The American Vice Presidency Reconsidered." "There may have been a partial exception in 2008."
With Ryan, Baumgartner said, "there's going to be some excitement out of the conservative base, but that's probably offset by the moderate Democrats who are a little nervous about some of the proposals Ryan talks about."
The polling pros at Gallup tell us that from 1996 to 2004, non-incumbent presidential candidates have received a boost in the polls of anywhere from 3 percentage points to 9 points shortly after naming a running mate. It's what's considered the vice presidential bounce. But what goes up, usually comes back down.
In 2008, there was no such bounce for Barack Obama after he selected Delaware Sen. Joe Biden; McCain gained only slightly immediately following the Palin pick.
The same type of bump happens after the presidential conventions. But what really shapes an election are things such as debate performance, campaign gaffes or outside events, from terrorism worries and war to the economy.
"I think it's very hard for a vice presidential candidate to actually be the game-changer," said Julian Zelizer, a professor of history and public affairs at Princeton University. "It's the major candidates who can do that, and events have the ability."
Four years ago, Zelizer noted, there was a financial crisis unfolding that contributed significantly to McCain's loss. On Sept. 15, 2008, less than two months from the election, the investment bank Lehman Brothers filed for the biggest corporate bankruptcy in American history, sending a sputtering economy into a tailspin under Republican President George W. Bush, whom many already were eager to replace. Those events coincided with -- and likely contributed to -- Obama's rising poll numbers that fall.
"The likelihood was that (McCain) was going to lose anyway," said Zelizer, adding that Palin "went out on the field and played poorly. But that's not a game-changer. She just continued the trend in the game."
Gone are the days when regionalism or the "favorite son" factor may even make a difference, as Texas Sen. Lyndon B. Johnson did for John F. Kennedy in the South in 1960. The electorate has grown far too polarized, Zelizer said, and most voters already know whether they're choosing the Republican or the Democrat, regardless of the No. 2.
For example, picking Sen. Rob Portman of Ohio, once considered a front-runner in the Romney running-mate contest, would have provided no guarantee that Romney would win Ohio.
In Ryan's case, the same goes for Wisconsin, Zelizer said. Wisconsin Republicans have displayed their strength this year, beating back an effort to recall Gov. Scott Walker. But at the same time Democrats still angry over that outcome could react strongly to the Ryan VP pick and work that much harder to get out the vote for Obama.
"Ryan can lose Wisconsin as much as he can win Wisconsin for Romney," Zelizer said. "So, again, it will come down to the Romney-Obama debates and their campaigns, rather than Ryan himself."
Joel Goldstein of Saint Louis University, a vice presidential scholar, agreed that the running-mate choice itself doesn't typically tilt the scales. However, there is one possible exception to that rule: "For it to make a difference you have to start with a close election," he said.
Isn't that just what we have this year?
"I don't think what Romney does is going to swing 10 percent of the vote or anything. I think you're talking about a few percent," he said. "That may not sound like very much, but on the other hand, in a close election, that can be the whole difference."
Walter Mondale may have been that difference in 1976, when he and Jimmy Carter narrowly defeated Gerald Ford and Bob Dole, Goldstein said. He noted that Mondale campaigned hard in states such as Ohio, Pennsylvania and Wisconsin, where the vice presidential candidate was popular, and the Democratic ticket won.
And, certainly, the choice does make a difference in other ways. Palin drew so much attention from the media and a public just getting to know her that the spotlight often shone brighter on her than on McCain and his message. The same could happen with Ryan, another relative unknown to most Americans, said Goldstein.
The pick can also offer clues as to what the presidential nominee perceives his weaknesses to be. In this case, was Romney worried about turning out a GOP base that has shown indifference toward him and thus chose Ryan, the primary author of a conservative budget plan that excites tea party Republicans? Perhaps, said Goldstein. Or maybe he's hoping Ryan's budgetary expertise will help steer the conversation away from Romney's own personal finances -- and personal style -- and back to the campaign's central issue: the economy.
After 2008, McCain advisers acknowledged that one goal of the Palin pick was to cut into Obama's lead among women voters. That didn't happen.
Nevertheless, in several studies of the "Palin effect," researchers found that her impact was more substantial than other vice presidential picks of the past. She excited the Republican base and rallied Democratic partisans. Her initial rise, then fall, in favorability ratings tracked closely with McCain's poll numbers.
But did she cost him the election? Researchers say no. One study, by analysts at Stanford and Duke, found that Palin may have cost McCain about 1.6 percent of the vote, hardly enough to change the outcome.
Still, the Palin legacy and the impact of a VP choice this time were very much on the minds of GOP faithful here in a state especially stung by McCain's loss in '08. They not only expressed some relief in the selection of Ryan; some firmly believed Romney's choice for VP would make a big difference.
Richard Morris, an insurance agent in Chandler, Ariz., had considered the Palin choice "a mistake." Ryan, on the other hand, "is a great pick," said Morris, 45. "It's one of those picks ... where you don't have to worry about: What are they going to say? Are they going to screw something up? You've got a guy who can really stand on his own."
"Conservatives are going to love it," said Kelly Jordan, 49, who works in construction and also lives in Chandler. "This is exactly what we need. We want the whole thing to be about the economy, and this is the guy who wants to rein it in."
Some Republicans may have felt "lukewarm about Romney," Jordan said. "Putting Ryan in there gives them that extra incentive and motivation."
Rigler, for one, felt an extra jolt of confidence following the announcement. "This really puts a good spin on things," said the 52-year-old who heads a small business alliance in the Phoenix suburb of Gilbert. "I think the Republicans who might have had a little bit of qualms about what they were going to do ... now they're going to go: 'Yes! This could be good.'
"I'm a supporter, but I didn't know if (Romney) could really pull it off with some of the undecideds."
It matters little to her what the experts, or history, tell us about the impact -- or lack thereof -- of a running mate. In this election, she said, "I really think it is game-changer."
Of course only time, and votes, will tell.