Gentile said former members of Congress often earn up to $50,000 per month on retainer for lobbying, and added, "We're getting Dan for a pretty darn good price."

Many trade associations hire outside lobbyists in addition to their internal legislative staffers, Gentile said. CUNA spent nearly $800,000 on external lobbying services in 2012, he said. In comparison, Gentile said bank trade associations like the American Bankers Association and Independent Community Bankers of America pay millions for outside lobbyists each year.

"The bankers' external lobby costs dwarf ours," he said.

Outside lobbyists often have existing relationships with key committee members that can be helpful, Gentile said. Others have backgrounds that relate to specific issues.

"You really want to be covered across the board, and maybe you can get somebody who is more specialized," he said.

CUNA also spent $946,992 for services from the Arlington, Va.-based consulting firm Greener and Hook. The firm, which according to its website specializes in political communications and strategy, also works with a number of prominent trade associations, private companies and Republican politicians.

According to the tax forms, membership dues were CUNA's largest source of income in 2012, accounting for $24.4 million in revenue. The trade's association services generated nearly $11 million, the Governmental Affairs Conference brought in $4.4 million and CUNA's publishing business earned nearly $3 million. Expenses include $28.4 million in compensation, $9.3 million to produce conferences, conventions and meetings and $1.7 million in payments to affiliates. Administrative expenses reported for CUNA's federal PAC were $738,582.

CUNA reported a $2.06 million profit in 2012, up from a $1.9 million profit in 2011.