Tom Perez is the chairman of the Democratic National Committee. The views expressed in this commentary are his own. View more opinion articles on CNN.

(CNN) Democrats won big in this year's midterm elections. We put hope on the ballot and voters across the country embraced our message, turning out in droves to elect the most diverse slate of candidates in history. It was a powerful repudiation of Donald Trump and the Republican politicians who march in lockstep behind him.

In response, GOP leaders could have used these losses as points of reflection to figure out what's broken within their ranks and why the American people rejected their agenda. Instead, Republican lawmakers have been engaged in a cynical and hypocritical power grab to overrule the will of the voters. This is a profoundly troubling assault on the very foundations of our democracy.

In Wisconsin, lawmakers have used their lame-duck legislative session to pass new restrictions on early voting -- an obvious attempt to reduce turnout among Democrats in the future. They've also passed a law to weaken the powers of Gov.-elect Tony Evers and Attorney General-elect Josh Kaul, in an effort to limit Democratic influence on future laws and prevent the state from withdrawing an anti-Obamacare lawsuit that seeks to remove protections for people with preexisting conditions

In Michigan, a similar story is unfolding. With a new Democratic governor, attorney general and secretary of state soon to take the oath of office, Republican lawmakers have aggressively moved to limit their governing powers. Secretary of State-elect, Jocelyn Benson, who campaigned on a promise to prioritize election transparency, may be stripped of her ability to enforce campaign finance law. That power would be handed to a newly created Fair Political Practices Commission, which would ostensibly not share Benson's priorities. Similar measures are being taken to try and shift authority from the new governor and attorney general to the Republican-controlled Legislature.

Meanwhile, in North Carolina, the FBI is investigating allegations that an operative working for Republican Mark Harris, who won the 9th Congressional District House seat by just over 900 votes, committed absentee ballot fraud. Many Republicans who have championed the passage of harsh voter ID laws in North Carolina and elsewhere across the country have been largely silent now that it looks like their allies are the true threat to the integrity of our elections.

It wasn't long ago that President Trump was making claims without evidence that his failure to win the popular vote was the result of millions of fraudulent votes. And it was only last month that Republican senators like Marco Rubio were crying foul over non-existent voter fraud in Florida. Now that we may have real evidence of election fraud within their party, their passion for the issue seems to have totally dissipated. The message is clear: Donald Trump and Republican leaders care more about clinging to power than protecting the voice of their constituents.

But the American people also sent a clear message last month: Republican leadership has failed. We demand accountability; we demand change. The GOP still refuses to listen. They've chosen to double down and abuse their power in the days before a new class of Democrats takes office. And, in doing so, they're undermining our democracy and threatening everything we value as Americans.

It's also worth noting that this win-at-any-cost attitude within the ranks of the GOP didn't form overnight. For years, Republicans have schemed to suppress Democratic turnout with racially targeted voter ID laws and aggressively gerrymandered districts. They have chipped away at our institutions with an eye on consolidating and entrenching their power, regardless of the will of the American people.

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Now that Democrats have taken back the House, and a number of governorships and state legislative chambers, we'll be able to restore some of the fairness, integrity, and accountability that Americans deserve from their leaders. But we shouldn't be the only political party working toward these ideals. There are, without question, Republicans of good conscience who are frustrated and angry with what their fellow party members are doing. They should stand up and speak out now. A good conscience does not alone make change. It must be paired with action.

Republicans, don't break our democracy. Fix your broken political party.