It's one of Massachusetts' boom industries — a recession-proof, $100 million-a-year enterprise that employs thousands of practitioners and support staff and shows no signs of waning.
It's product? The art of swaying the minds of lawmakers, candidates and the state's most powerful political figures.
Political lobbying has found fertile ground in Massachusetts.
In 2005, there were just over 800 lobbyists registered with state. By 2012, that number had soared to more than 1,600, according to an Associated Press review of lobbying records filed with the state secretary's office.
That's eight lobbyists for each member of the Legislature.
In part, the increase is due to a change in the definition of a lobbyist. The broadened definition, prompted by a 2009 ethics law, forced many individuals who had avoided the label to officially register.
The increase is also recognition of the extraordinary level of lobbying in Massachusetts, according to state Secretary William Galvin, whose office oversees lobbyists.
"It's a native species that flourishes here very well," Galvin said.
Lobbyists are quick to defend their work, saying they're not only helping make sure the voices of their clients are heard, but in many cases are helping educate lawmakers on topics or areas where they may have little expertise.
One way lobbyists seek the attention of lawmakers is to donate directly to their campaigns.
In 2005, lobbyists contributed about $943,540 to the campaigns of lawmakers and candidates, according to the AP review.
That's an even more impressive total considering that, by law, lobbyists can't contribute more than $200 each year to an individual lawmaker or candidate. In 2005, that translated into nearly 6,500 individual donations of varying amounts.
By 2012, the total donated by lobbyists to lawmakers topped $1.2 million, or about 8,200 individual donations.
And direct donations to lawmakers are only the tip of the lobbying iceberg considering the total amount spent on the industry in Massachusetts, a modest-sized state with a full time Legislature and a reputation for ambitious lawmaking.
In 2012, the total amount spent on lobbyists' salaries and on related expenses like meals, entertainment and transportation topped $118 million, up from the $71 million spent in 2005.
That's far more than the total budget for the operations of the entire Massachusetts Legislature - just over $61 million for the just-completed fiscal year.
Galvin said what makes the amount spent on lobbying even more unusual is the relatively few major bills that pass each session.
"The question that arises is what are these people doing?" he said. "Are they being paid to prevent bills from becoming law?"
The donations from lobbyists to lawmakers appear to have peaked in 2010, when the total neared $1.4 million, or more than 9,300 individual donations.
That was also the year of some of the fiercest political wrangling over a bill to allow casino gambling in Massachusetts.
While the bill was signed in 2011, an earlier version collapsed midway in 2010 despite a concerted push by supporters. After the defeat, backers immediately began pushing for a new, compromise bill.
The overall pace of lobbying doesn't show any signs of letting up. Midway through 2013, lobbyists had contributed more than $788,000, according to Galvin's office.
Two of the biggest targets of lobbyist's political contributions are the two most powerful members of the Legislature, House Speaker Robert DeLeo and Senate President Therese Murray.
In 2012, DeLeo received about $47,910 in donations from lobbyists, while Murray received about $48,170.
DeLeo and Murray have said donations from lobbyists don't affect their political decision-making.
Gov. Deval Patrick, who has announced he would not seek a third term, received about $5,350 in donations from lobbyists last year
Former Lt. Gov. Timothy Murray, who resigned earlier this year, but in 2012 was considered a possible front-runner in the 2014 governor's race, pulled in about $24,550 from lobbyists.
Martha Coakley, who is considering a run for governor, collected about $13,460, while state Treasurer Steven Grossman, who has announced his candidacy, received about $5,225.
But some of the biggest targets remain in the Legislature, especially lawmakers responsible for crafting the House and Senate versions of the state budget, essentially deciding what will and won't be funded with taxpayer dollars.
Senate Ways and Means Chairman Stephen Brewer received about $15,535 from lobbyists last year, while his counterpart, House Ways and Means Chairman Brian Dempsey collected about $32,050.
It's not just the number of lobbyists that has risen over the years.
The number of clients - all those companies, organizations or individuals who hire lobbyists to convey their messages to lawmakers - has also climbed from 1,055 in 2005 to 1,368 in 2012.
At the same time, the number of firms engaged in lobbying in Massachusetts has also ticked up from 128 in 2005 to 205 last year. In some cases an entity and an individual lobbyist overlap if the lobbyist is also head of the lobbying firm.
Here's how much registered lobbyists gave in direct contributions to the campaigns of lawmakers, candidates and other top political figures in Massachusetts during the past eight years:
Source: Massachusetts Secretary of the Commonwealth's Office.
This program aired on August 18, 2013. The audio for this program is not available.