• Current and former lawmakers filed a class-action lawsuit seeking $50 million from the government.

• They argue their salaries, stuck at $174,000 since 2009, have been "unconstitutionally suppressed."

• The suit's being led by Ken Cuccinelli, an ex-Trump official who doesn't care how unpopular this is.

You may have heard that some lawmakers think the $174,000 annual salary for rank-and-file House and Senate members is too low.

According to a new class-action lawsuit, it's gotten to that point in part because lawmakers' wages have been "unconstitutionally suppressed" — and current and former lawmakers may be collectively entitled to $50 million in damages as a result.

"This is a vindication of the Constitution and the principles the founders were trying to achieve," Ken Cuccinelli, the lawyer and former Trump White House official leading the suit, told Business Insider in an interview.

Cuccinelli's lawsuit, first reported by POLITICO, was filed last week on behalf of Republican Rep. Rick Crawford of Arkansas and a trio of ex-lawmakers from both parties — and it hinges primarily on the 27th Amendment to the US Constitution:

No law, varying the compensation for the services of the Senators and Representatives, shall take effect, until an election of Representatives shall have intervened.

The amendment was first submitted to the states for ratification along with the amendments that later became the Bill of Rights — but it wasn't ratified until 1992, over 200 years later.

The suit argues that Congress has violated the US Constitution by routinely denying lawmakers an annual cost of living adjustment in their salaries.

Since 2009, rank-and-file lawmakers' salaries have remained flat at $174,000 because government funding bills have included a provision explicitly blocking a modest pay increase that would otherwise happen. Almost every year, Congress votes on those bills — and they take effect — without an election happening in between.

Because lawmakers' salaries are not keeping pace with inflation and increasing under the cost of living adjustment that would otherwise take place, the suit argues that their wages are being "varied" by being effectively suppressed, thus violating the 27th Amendment.

"You've got a situation now where you either have to be rich to go into Congress, or you have to sacrifice your family," said Cuccinelli, noting that lawmakers are typically expecting to maintain two separate residences — one in DC, and one in their home state.