WASHINGTON — The $550 million spent by outside entities on the 2004 election was simultaneously effective and devastating, two political research centers told a Washington, D.C., audience Thursday.

On one hand, spending by so-called 527s probably allowed Democratic challenger John Kerry to keep the race close last year when it looked as if Bush was pulling away for an easy win.

On the other, it was an impeccably timed Republican 527 ad campaign — the Swift Boat Veterans and POWs for Truth — that probably played the biggest role in the outcome. That and the fact Kerry did not respond quickly enough.

"It took Kerry off message" and gave a strategic advantage to Bush, said Brigham Young University political scientist David Magleby, who with the Center for the Study of Elections and Democracy at BYU and the Center for Public Integrity in Washington, D.C., have been examining the nuances of campaign spending during 2004 election.

"The Swift Boat Veterans attack was masterful," Magleby said. "This group delivered a message that the Bush campaign and the RNC could not, and Bush got the best of both worlds because he could decry 527s and benefit from their activities at the same time."

Researchers estimated that 75 percent of voters saw and remembered the ads.

The organizations are called 527s after Section 527 of the Internal Revenue Code, which grants tax-exempt status to political committees at the national, state and local level. A broad interpretation has opened the door for all types of groups to actively influence elections and policy debates, but with the caveat they do not explicitly advocate — at least in theory — for the defeat or election of candidates.

Magleby and researchers at the Center for Public Integrity revealed some of their findings Thursday during a press conference at the National Press Club:

• There were 257 groups active during the last election cycle, raising $534.6 million and spending $550.7 million.

• Democratic 527s outspent Republican 527s by a two-to-one margin.

• Two-thirds of the money raised went to help candidates for federal office.

• Corporations did not give much money to 527s organized to help federal candidates, but instead shifted their donations to 527s focused on state candidates and issues.

• 527 committees were professionally managed, easy to set up and were "parallel campaigns" to the official candidate campaigns in every sense.

• The role of 527 committees is only going to get larger and more influential in future elections as groups better understand what they can and cannot do under federal campaign reforms.

The massive amounts of money raised and spent by 527s has raised eyebrows and concerns among campaign watchdogs, who say the loophole in the IRS code creates a mechanism whereby political contributions are unregulated and unlimited.