Based on recent precedent, Democrat Ron Barber's special election triumph in a Republican-heavy Arizona congressional district portends little or nothing about the outcome of this fall's battle for control of the House.
That didn't stop either party from posting rival claims: Democrats cast the race as a referendum on Republican proposals for Social Security and Medicare. Republicans stressed that Barber's victory came after he emphasized his differences with President Barack Obama on health care and other issues.
There is some truth in both claims.
Yet it's also the case that nowhere else this November will former Rep. Gabrielle Giffords be a central figure, successfully bequeathing to a former aide the seat she held when she was injured in a 2011 assassination attempt.
"Special elections sometimes mean something but not very often," said Steve Elmendorf, who was the top aide to former House Democratic Leader Dick Gephardt at a time when the party struggled unsuccessfully to take control of the House away from Republicans.
"They happen in the middle of years. They're generally low turnout. ... Whoever wins always makes a big deal about what it means. But I think looking back it's hard to find examples where they mean anything."
David Winston, a Republican pollster who worked for former House Speaker Newt Gingrich, generally agreed. He said that while there are some special elections that may indicate a broader trend, "you have to be very careful in terms of looking at the context and dynamic of the race."
It isn't usually clear until the next general election whether a local race reflects a national trend.
In the spring of 2010, the two political parties each spent $1 million in hopes of winning a race to replace the late Rep. John Murtha in a conservative, Democratic district in southwestern Pennsylvania.
Former Murtha aide Mark Critz triumphed, and Democrats said it debunked Republican "bluster about building a wave" at a time when the economy was weak and controversy was building over Obama's health care proposals.
Not a chance.
Five months later, Republicans won a House majority in a huge landslide that swept dozens of Democrats from office.
In a postscript, Critz won re-election that fall, demonstrating conclusively that his fate and his party's were not closely linked.
In fact, most of the dozens of special elections held in recent decades have proven to be political snoozes in which custody of a seat transfers from one Republican to another, or one Democrat to a second.
Even when a seat switches parties, it doesn't necessarily mean much nationally.
Former Democratic Rep. Anthony Weiner of New York, who quit a little more than a year ago in a sexting scandal, was replaced by Republican Bob Turner in a district formed by parts of Queens and Brooklyn.
The GOP thought so little of Turner's chances of surviving in 2012 that state officials agreed to eliminate the district when boundaries were drawn to account for the 2010 census.
In recent years, the most notable example of a special election serving as a barometer of national trends took place in Kentucky in 1994, when Republican Ron Lewis succeeded the late Democratic Rep. William Natcher.
The seat_like the House itself _ had been in Democratic hands for decades, and the race was a harbinger of the landslide that fall that propelled the GOP to a majority for the first time in 40 years.
Whatever its value as a national barometer, a contested special election serves as a warm-up of sorts for the two political parties to test their organizations, gauge the effectiveness of television commercials on public opinion and build enthusiasm among donors.
In the case of Arizona, Democrats test-marketed commercials that accused Republican Jesse Kelly of wanting to cut taxes for millionaires and phase out Social Security and Medicare. Barber, echoing the same themes, promised "no cuts, no way" to either program.
Referring to the budget that cleared the Republican-controlled House earlier in the year, Democrats circulated a post-election memo that said "every Republican incumbent shares Kelly's vulnerabilities" on the same issues, and 84 of those districts are more Democratic than the one Barber won.
For its part, the National Republican Congressional Committee ran ads that said Barber supported the health care law that Obama won from Congress in 2010 and includes cuts totaling $500 billion from Medicare. "Rubber stamp Ron Barber," they called him, a ready vote for Obama's policies.
Their commercials showed pictures of Barber, Obama and House Democratic Leader Nancy Pelosi, a linkage meant to be unflattering, and a reminder of a tactic that many Democrats blamed for the loss of their seats in 2010.
Whatever the national significance of the race, if any, Democrats moved swiftly to capitalize among donors.
"We did it," the House Majority PAC wrote in an email to supporters that sought contributions for the fall campaign.