NEW YORK (CNNMoney.com) - Those who run the White House and Congress make in the low- to mid-six-figures. Those who run the organizations that seek to influence public policy easily can make more -- in some cases far more.

The National Journal, a nonpartisan weekly publication on politics and policy, recently published its biennial salary survey of annual pay packages pocketed by the leaders of 597 trade associations, think tanks, labor unions and professional societies.

Using information reported for 2003 and 2004 to the IRS and the Labor Department, the National Journal found plenty of million-dollar-plus total pay packages. This year the number reached 48, up from 18 in 2000.And 145 executives now make $500,000 or more, up from 98 in 2000.

In some instances, an executive's package may be higher than normal in the year reported due to a one-time payment for deferred compensation, severance and retirement benefits.

That's what accounts for much of the $11 million pay package enjoyed by Jack Valenti, who retired in 2004 from the Motion Picture Association. His compensation for the year accounted for just under $2.4 million of his total pay.

Ditto for U.S. Chamber of Commerce CEO Thomas Donaghue. He received $6.8 million, nearly three-quarters of which was due to supplemental retirement benefits accrued over 19 years.

Others who received exit payouts or retirement benefits included Carl Feldbaum of the Biotechnology Industry Organization, Matthew Fink of the Investment Company Institute, Alan Holmer of the Pharmaceutical Research and Manufacturers Association, and Craig Fuller of the National Association of Chain Drug Stores.

All the organizations surveyed are nonprofits. They can make their money in a variety of ways, including through membership dues, like the National Association of Realtors, and ticket sales and booth fees for conventions, like the Consumer Electronics Association, said Bara Vaida, who conducted the survey.

And the organizations are paying their leaders more because "their efforts, particularly on behalf of corporate America, have greatly boosted their members' bottom lines. In addition, the associations' influence has grown since President Bush took office, as many CEOs have helped to raise money for lawmakers from both parties and have vigorously supported the administration's policy agenda," Vaida wrote.

Plus, the demands of the job have expanded beyond advocacy to include providing member benefits in an increasingly competitive environment and polishing an industry's public image, sources told Vaida.

Not everyone in the survey pulls down sky-high pay. Executive directors of public-interest groups made the least, earning a median salary of $184,881.

But some don't come anywhere close to making six figures. The president of People for the Ethical Treatment of Animals makes just $35,664 a year.

Below is a list of the top 50 total pay packages. The National Journal survey also broke out pay by compensation only. For a look at that list and at Vaida's full report, click here.