Hawkins said CUNA has not made any formal decisions on independent expenditures in the midterm election.

As illustrated in the infographic above (click to enlarge), control of the Senate could shift to the Republicans.

Sen. Mark Udall (D-Colo.) is locked in a tight race with Rep. Cory Gardner (R-Colo.) for the seat he has occupied since 2009. Udall's credit union backing is bold and tenacious and he has supported credit unions since his early days in the House when he cosponsored CURIA each time it ran, said Christopher Kemm, vice president of political affairs for the Mountain West Credit Union Association.

"How many elected officials can withstand bank industry pressure to discard his support for credit unions and continue to keep introducing a credit union specific bill? I know of one," Kemm said. "Senator Udall, and it is his dedication to helping consumers and small businesses that has driven him to try to get a bill passed."

NAFCU contributed $7,000 to Udall's campaign and CUNA donated $10,000 in addition to $10,000 for his leadership PAC.

"We are happy to support a member of Congress who is willing to introduce stand-alone legislation like member business lending, which would help credit unions be even more active in making loans to small businesses," Marisic told CU Times.

Read more: Key races in Alaska, West Virginia and Michigan …

The trade groups are also backing Sen. Mark Begich (D-Alaska) in his re-election campaign against Republican challenger Dan Sullivan, former Alaska attorney general. NAFCU, which donated $3,000, said Begich has been a consistent supporter of the credit union tax exemption. CUNA contributed $10,000 to Begich for the midterm election cycle.

"We think that it is important to elect more pro-credit union candidates to office, specifically to the Senate," Marisic said. "Begich has sponsored multiple pieces of credit union legislation, including privacy notice requirements, member business lending, supplemental capital, and was also a vocal proponent of our tax exemption."

NAFCU and CUNA are also supporting Rep. Shelley Moore Capito (R-W.V.), Chairman of the House Subcommittee on Financial Institutions & Consumer Credit, in her race against Secretary of State Natalie Tennant (D-W.V.). CUNA donated $10,000 and NAFCU donated $2,500 for this election cycle.

"NAFCU feels that getting members of Congress like Shelley Moore Capito and Gary Peters elected to the Senate is important," Marisic said. "Thanks to their time on the House Financial Services Committee, they are knowledgeable of our issues and supportive of credit unions."

NAFCU hopes that electing people like Capito and Peters to the Senate will push pieces of legislation that passed out of the House such as privacy notice requirements and interest on lawyers trusts accounts over the finish lines in the Senate, Marisic noted.

Ryan Donovan, CUNA senior vice president of legislative affairs, said Capito has developed a great relationship with West Virginia credit unions.

"She has led the effort on examination fairness and was co-sponsor of our ATM disclosure bill in the Congress. She's had a leadership position on the Financial Services Committee and that's provided us an opportunity to get to know her better and give her an opportunity to get to know credit unions better," he said.

Donovan also pointed out that Reps. Gary Peters (D-Mich.) and Bruce Braley (D-Iowa) co-sponsored legislation to raise the MBL cap in the last three Congresses. CUNA donated $10,000 to Braley and Peters. NAFCU contributed $1,000 to Braley and $2,000 to Peters, a member of the House Financial Services Committee.

"Peters publicly supported the credit union tax exemption and he signed the King-Meeks letter on risk-based capital," said Donovan, referring to the letter written by Reps. Peter King (R-N.Y.) and Gregory Meeks (D-N.Y.), to the NCUA about the proposed risk-based capital rule. Braley signed the letter along with 75% of the House.

CUNA is also involved in the Montana Senate Race between Republican Rep. Steve Daines and Democratic State Rep. Amanda Curtis. CULAC donated $10,000 to Daines while NAFCU said it has not contributed funds to either candidate in the race.

"Congressman Steve Daines has provided explicit support of credit unions' tax exemption. He has come under fire from the for-profit banking lobby for his stance but has not wavered," said Tracie Kenyon, president/CEO of the Montana Credit Union Network.

CUNA is behind former Gov. Mike Rounds (R-S.D.) with a $10,000 contribution against Rick Weiland (D-S.D.). NAFCU said it has not been involved in the Rounds race. Sen. Tim Johnson (D-S.D.), chairman of the Senate Banking, House and Urban Affairs Committee, who currently holds the seat,, announced his retirement in March 2013.

"The former Governor and his wife have been long-time members of Oahe Federal Credit Union, Pierre, S.D.," said Jeff Olson, political affairs and public relations director at the Credit Association of the Dakotas. "Basically, this race is over. Even Harry Reid has conceded this one to Rounds."