This article will help explain what the professional lobbyists do.
K Street in Washington, DC, is where most of the offices are of professional lobbyists.

Read the full article here... Washintgon Post

note that the article is from 2005
We've gone through scandals of lobbyists like Jack Abramoff, who is now in federal prison. Click the link and read the whole article to get an idea of what Lobbying has been all about in the last 8 yeas under Bush.

"The Road to Riches Is Called K Street
Lobbying Firms Hire More, Pay More, Charge More to Influence Government

...Wednesday, June 22, 2005; Page A01

To the great growth industries of America such as health care and home building add one more: influence peddling.

The number of registered lobbyists in Washington has more than doubled since 2000 to more than 34,750 while the amount that lobbyists charge their new clients has increased by as much as 100 percent. Only a few other businesses have enjoyed greater prosperity in an otherwise fitful economy.

The lobbying boom has been caused by three factors, experts say: rapid growth in government, Republican control of both the White House and Congress, and wide acceptance among corporations that they need to hire professional lobbyists to secure their share of federal benefits.

"There's unlimited business out there for us," said Robert L. Livingston, a Republican former chairman of the House Appropriations Committee and now president of a thriving six-year-old lobbying firm. "Companies need lobbying help."

Lobbying firms can't hire people fast enough. Starting salaries have risen to about $300,000 a year for the best-connected aides eager to "move downtown" from Capitol Hill or the Bush administration. Once considered a distasteful post-government vocation, big-bucks lobbying is luring nearly half of all lawmakers who return to the private sector when they leave Congress, according to a forthcoming study by Public Citizen's Congress Watch.

Political historians don't see these as positive developments for democracy. "We've got a problem here," said Allan Cigler, a political scientist at the University of Kansas. "The growth of lobbying makes even worse than it is already the balance between those with resources and those without resources."

continued at link