When organizers of three Colorado initiatives targeting government spending launched a petition drive to get on the November ballot last year, they didn’t rely solely on amateurs, according to an analysis of data from the Colorado Secretary of State and the Washington D.C.-based Ballot Initiative Strategy Center.

The initiative backers used experienced circulators to help gather nearly half a million signatures — almost double the number required — to get Amendments 60 and 61 and Proposition 101 on the ballot, the data show.

And those circulators were no strangers to such efforts.

The signature gatherers who worked in Colorado had the same names as those who gathered signatures to get anti-tax measures on the ballot in Missouri, Oklahoma and Nebraska in 2005 and 2006, according to a database maintained by the   center. The center several years ago began reviewing and tracking information from petitions submitted to states.

Those anti-tax measures in  Missouri, Oklahoma and Nebraska, all of which failed for various reasons, carried a name that’s familiar to many Coloradans: the Taxpayer’s Bill of Rights, or TABOR.

Colorado Springs resident Douglas Bruce authored Colorado’s Taxpayer’s Bill of Rights, which was approved by Colorado voters in 1992. The amendment limits government taxation and growth.

Five of the circulators who worked on the out-of-state TABOR initiatives have the same name as five circulators who in 2009 lived in a house on East Boulder Street in Colorado Springs owned by Bruce. They’ve since moved out and couldn’t be located for comment.

Those Boulder Street residents collected signatures for Amendments 60 and 61 and Proposition 101, Secretary of State records show. And several of them also collected thousands of signatures for Issue 300, a Colorado Springs measure authored by Bruce and approved by voters last fall, which effectively ended the city’s stormwater enterprise.

Bruce, contacted by telephone and email, declined to comment on the fact that tenants living in his house were involved in TABOR petition drives in other states. “Do NOT email me or call me again, EVER,” he said in an e-mail.

Joel Foster, a member of the Ballot Initiative Strategy Center, said collecting signatures for ballot initiatives is no longer a grassroots effort but rather a booming business. “There’s lots of money being spent this way. More and more professionals are involved, and there are fewer and fewer grassroots folks.”

Petition circulators can earn $50,000 to $100,000 a year, and often move as a crew from state to state, he said. “Their primary purpose is to make as much money as they can,” Foster said.

“They tend to live together and travel together,” Foster said. “Signature gathering firms will call them when they need them to work on campaigns.”