Speculation is running at a fevered pitch that 2008 presidential candidates Sen. Barack Obama and Sen. John McCain are poised to roll out their respective choices for a running mate any day now.
Pollsters are quick to point out that the choice of a vice presidential candidate ultimately weighs little on the minds of voters when they step into the voting booth on election day.
But done well, a vice-presidential announcement can bring a welcome boost to any campaign and days of positive media attention. It is a critical moment that can be a boost, or a stumble.
"This is the first presidential decision that a nominee for president makes," Democratic strategist Tad Devine told ABC News' Claire Shipman recently. "They use that as a proxy for judging whether or not the candidate is capable of making presidential-level decisions."
It's a high-stakes decision that will be endlessly evaluated by political reporters, pundits and the public.
"It's a huge opportunity for these candidates," said Sara Taylor, a Republican strategist and former White House political director for the Bush administration. "Each of these guys gets a chance to sort of add to the narrative with their choice of these individuals, so it's huge."
McCain will reportedly announce his running mate on Aug. 29 in the battleground state of Ohio, one day after Obama accepts the Democratic nomination in Denver and just days before the Republicans' own convention.
Obama is expected to announce his running-mate before the end of this week, just days before the Democrats gather for their convention in Denver next Monday.
"Both McCain and Obama want to maximize the media coverage of their VP pick," said Nathan Gonzales, political editor of the Rothenberg Political Report, a Washington DC-based nonpartisan political newsletter.
Obama to Alert Supporters Via Text Message
Obama's campaign has promised supporters that they'll be the first to know his pick via text message and e-mail blast.
In a similar move, 2004 Democratic nominee Sen. John Kerry, D-Mass., e-mailed millions of supporters letting them know he was picking Sen. John Edwards, D-N.C. The email came in advance of his formal public announcement five days before the party's convention.
Kerry and Edwards then embarked on a four-day rollout that was covered widely by television news media, boosting their profile going into the 2004 Democratic National Convention in Boston and giving Kerry a 4 percent bump in public opinion polls.
Successful VP Rollout Could Boost Campaigns in Polls
The right choice could help a presidential wannabe win over voters in key battleground states or fill in experiences the candidates themselves may lack.
Also, a successful VP pick could give the candidates their first opportunity to reset what is shaping up to be a close race, with Obama at 47 percent support from likely voters and McCain at 42 percent support, according to the latest poll released today by Quinnipiac University.
A well-received veep pick could generate a positive bounce in the polls that lasts several days, if not longer.
Obama and McCain can expect to gain anywhere from three to nine percentage points in public opinion polls following their VP rollout, according to a recent Gallup analysis of poll results going back to 1996.
When former Vice President Al Gore selected then-Democratic Sen. Joseph Lieberman of Connecticut as his running mate in 2000, the duo cut then-Gov. George W. Bush's post-convention lead in half, according to Gallup.
Press Corps Whipped Into Veep Frenzy
The press corps has whipped itself into a frenzy trying to figure out who the picks will be and how the candidates will reveal their picks to the public. McCain's short list is rumored to include Minnesota Gov. Tim Pawlenty, former Massachusetts Gov. Mitt Romney, former Pennsylvania Gov. Tom Ridge and Lieberman, now a registered Independent.
Obama's potential Democratic veep list is thought to include Indiana Sen. Evan Bayh, Delaware Sen. Joe Biden and Virginia Gov. Tim Kaine.
A big rule for any presidential candidate is to vet potential running mates thoroughly. Presidential candidates have been burned in the past by their veep choices.
Obama's vice presidential search team -- led by Caroline Kennedy, daughter of President John F. Kennedy, and former deputy Attorney General Eric Holder -- has been researching the backgrounds of potential picks for weeks.
Arthur Culvahouse, a Washington D.C. lawyer who was President Ronald Reagan's White House counsel from 1987 to 1989, is heading McCain's search team.
Campaigns Try to Avoid Wrong VP Choice
Historically, there have been missteps with running mate picks.
"Not all vice presidential rollouts have provided the campaign the positive news it sought," Kathleen Hall Jamieson, the director of the Annenberg Public Policy Center at the University of Pennsylvania, told ABCNews.com.
Campaigns are mindful of avoiding a repeat of negative press received by Walter Mondale's 1984 running mate Geraldine Ferarro, whose husband's refusal to release his tax returns overshadowed positive press coverage of her as the first woman selected as a running mate.
George McGovern's 1972 vice presidential pick, Thomas Eagleton, was forced to withdraw from the election after reports emerged that he had been treated for depression with shock therapy.
Any potential vice presidential candidate must help the candidate in a series of vice presidential debates and avoid embarrassing gaffes like the one made by 1988 Republican vice presidential candidate Dan Quayle during a debate.
Defending charges that he lacked experience for the White House, Quayle said during the 1988 debate: "I have as much experience as Jack Kennedy did."
Democratic vice presidential candidate Lloyd Bentsen, running mate to Michael Dukakis, shot back, "Senator, I served with Jack Kennedy: I knew Jack Kennedy; Jack Kennedy was a friend of mine. Senator, you're no Jack Kennedy."
Former President Richard Nixon settled on Spiro Agnew, who was later forced to resign the vice presidency after being charged with accepting bribes totaling more than $100,000.
But if done right, the art of the vice presidential rollout could give the candidates an opportunity to drive the narrative of their campaign -- if only for a short while.
"The success of the rollout all depends on the person they choose," Gonzales said. "How the vice presidential candidate is received and analyzed by the media probably will be the biggest factor in determining the success of it."