Lobbyists are going on the offensive after becoming the favorite whipping post of Democratic presidential candidates, saying they are a necessary and valuable resource for legislators making critical decisions with wide-ranging implications.

Lobbyists play a variety of roles from explaining to lawmakers the position of their interest group to critiquing legislation to, at times, sitting down with congressional staff and helping write legislation, say some political experts.

"When you have a regulatory state you will have lobbyists, and you should," said Michael Barone, a senior writer at U.S. News & World Report (search).

Patrick Basham, senior fellow at CATO Institute's Center for Representative Government (search), said oftentimes lobbying groups perform activities that are directly meant to help the public.

"You get legislation such as McCain-Feingold [campaign finance reform enacted into law in 2002] largely written or vetted by the main representatives for the campaign finance industry — various good government organizations," Basham said.

But some watchdogs say lobbyists have a potentially dangerous influence on politics because they advocate the interests of specific groups rather than that of the public at large.

"You end up having narrowly tailored bills that are good for one interest or even one company," Bill Allison, managing editor of the Center for Public Integrity (search), told Foxnews.com.

"Certainly, lobbyists do play an important role in educating members and their staff on complicated issues. The danger is when they're given a pen and paper and told to write their wish lists," said Sheila Krumholz, research director for the Center for Responsive Politics (search).

Lobbying is a big business in Washington. According to the Center for Responsive Politics, companies, labor unions and other organizations spent $1.45 billion on lobbying Washington in 1999. Statistics for 2000 showed that industries spending the most were finance, insurance and real estate at $214 million and health care at $197 million.

On the campaign trail, the Democratic presidential hopefuls have been slamming lobbyists for their allegedly overwhelming influence on Washington. The American League of Lobbyists (search) decided to fight back, sending a letter to the candidates on Feb. 3, asking them to tone down such statements as one by John Edwards in which he said, "We ought to cut them off at the knees" and a vow by John Kerry to "free our government from the grip of the lobbyists."

"Lobbying is an essential part of the American political process protected by the First Amendment to the U.S. Constitution and one of the major ways that politicians are held accountable to the people," wrote Deanna Galek, president of the non-partisan league, which represents more than 500 lobbyists, including those who work for trade associations, corporations, public-interest groups, labor unions and law firms.

"Lobbyists represent all points of view on the major issues that confront the country and the Congress — environment, labor, the elderly, teachers, veterans as well as businesses, to name just a few," Galek wrote.

Lobbyists also represent a huge number of voters who are members of special interest groups, including public school teachers, the National Rifle Association, union members and other organizations. However, Basham said, most voters don't realize their impact in Washington, which makes it easier for politicians to lash out against the groups.

"It's good politics because the average voter has this notion of this corrupt system, and there are these unknown entities known as lobbyists, special interest groups. The average voter doesn't realize that they themselves probably belong to a special interest group represented in Washington. There is a general, vague sense of corporate shenanigans, and things aren’t quite run the way they should be, and the Democratic [presidential] candidates are tapping into that," Basham said.

Allison suggested that lobbyists should not be educating lawmakers, public servants would better fill that role.

"We spend a tremendous amount on congressional staff. If you're in a situation where you need a paid lobbyist and your staff can't explain it, then I think we have a problem. If it's coming from a lobbyist, can you really trust it?" Allison asked.

Critics say a problem also arises by the incestuous nature of lobbying. Lobbyists usually are people with access. Sens. Bob Dole and George Mitchell and Reps. Vic Fazio, Bob Livingston and Bob Michel are a few of the prominent former lawmakers who now punch the clock on K Street.

"It's commonsensical to suggest that if you’ve either just left a committee position or left a senior position with a senior congressman that you're going to have greater access in the short term. You are going to get your phone calls answered. You are going to get your meetings set up," Basham said.

"Access is the critical element. Their contributions are not enough to generally buy votes or buy policy. Who they are and what doors they can open is probably far more powerful than their contributions," Krumholz said.

Basham said candidates ought to be careful about slamming one another for their ties to special interest groups because both parties are deeply linked to them.

"I think it's very much a wash. The Democrats are no worse than the Republicans, but they're no better," Basham said.

Allison called lobbyists "incredibly influential," and said the fact that they command such large salaries demonstrates how highly industries value them. However, other experts characterized their influence differently.

Lobbyists are less influential "than the media headlines and conventional wisdom would suggest," Basham said. "Whether it's behind the scenes lobbying or campaign contributions, it's very hard to find examples of a direct connection between a lobbyist pitch for a certain vote, a certain direction and that outcome."