"'One member, one vote' is a critical component not only to the membership structure but also to the credit union philosophy; a member of greater means has just as much right to the use of the credit union as a member of small means," Cheney wrote.

And, despite all the evolution and development that has taken place at credit unions over the past century, one thing that has remained the same is credit unions' cooperative ownership structure and democratic governance, he said. 

"The members of the credit union own the credit union; a bank is owned by its shareholders. This means what motivates credit union leaders and bank executives is different, and it boils down to this: credit unions use members' money to help members; banks use customer's money to make money for shareholders," Cheney wrote.

When the bank lobby calls on Congress to tax credit unions, what they are really demanding of Congress is to do away with credit unions, Cheney wrote, because that would be the end result. 

"If taxed, a very significant number of larger credit unions are expected to convert to banks and an equally significant number of smaller credit unions would simply liquidate," he said. 

Remaining credit unions would have to pass the costs of taxation on to their members because they are wholly owned cooperatives, increasing the cost of accessing mainstream financial services. 

"As a result, the ability of millions of American consumers and small businesses to rely on a system of financial cooperatives for affordable access to mainstream financial services, which is made possible by the credit union tax exemption, undoubtedly would be jeopardized," Cheney wrote to the congressmen. 

"When that outcome is considered side-by-side with the credit unions' historic record of member service and mission fulfillment, the absurdity of the bank lobby's demand is self-evident," he concluded.