A timeline of Donald Trump's election denial claims, which Republican politicians increasingly embrace

This story is part of the ABC News series "Democracy in Peril," which examines the inflection point the country faces after the Jan. 6 attacks and ahead of the 2022 election.

Six years ago, Texas Republican Sen. Ted Cruz responded in no uncertain terms to then-candidate Donald Trump's claims of a rigged GOP primary election, for which Trump didn't have evidence.

"Apparently, when anyone votes against him, it’s an act of theft," Cruz, who was running against Trump, told Glenn Beck in April 2016.

Some five years later, Cruz rose on the floor of the Senate in support of Trump's renewed but unfounded argument that the presidential election he had recently lost was rigged against him. In a speech on Jan. 6, 2021, Cruz said he was voting not to accept the Electoral College results showing Trump was defeated because so many Americans had been persuaded that Trump had, in fact, won.

"For those who respect the voters, simply telling the voters, 'Go jump in a lake, the fact that you have deep concerns is of no moment to us' -- that jeopardizes, I believe, the legitimacy of this and subsequent elections,” Cruz said in that speech, mere minutes before an angry mob breached the Capitol.

He was not the only Republican to change his statements on election integrity or to embrace the argument that elections themselves must be questioned: A new FiveThirtyEight analysis found that nearly 200 Republican nominees for office this year have denied the 2020 election results, which were repeatedly upheld by various audits, judges and local officials from both parties.

Trump himself, from the 2016 primary through today, has made election denialism a central part of his campaigns and of Republican politics -- and also helped make it a motivating issue for other politicians, including those who once had criticized him for it.

And while ABC News/Ipsos polling this year showed a majority of Americans sharply disapproved of Trump's role in attacking the 2020 election, including a fifth of Republicans, that same survey also indicated a majority of Republicans believed he didn't really lose.

Here is a timeline of how his attacks on elections took hold in the mainstream.

2016

Trump has a long history of crying foul in contests he doesn't win, including previously saying that the "Emmys are all politics" after his reality TV show, "The Apprentice," never won an award. He also labeled then-President Barack Obama's 2012 reelection "a total sham."

He leaned on that same tactic in 2016 during the GOP primaries, including the Iowa and Colorado caucuses, which he lost to Cruz.

"Based on the fraud committed by Senator Ted Cruz during the Iowa Caucus, either a new election should take place or Cruz results nullified," Trump tweeted that year without providing evidence. Cruz rebuffed Trump at the time, telling supporters at one event: "Donald, it ain’t stealing when the voters vote against you -- it is the voters reclaiming this country and reclaiming sanity."

Trump later said the Colorado caucuses were similarly "rigged" and dismissed opponent Hillary Clinton's victory over Vermont Sen. Bernie Sanders in the Democratic primary.

Yet it was during and after the 2016 general election, in which he lost the popular vote to Clinton but won the Electoral College, that he began making claims of fraud more consistently.

In the final weeks of the 2016 race, he refused to confirm whether he would accept a defeat. Afterward, he insisted he had only lost the popular vote through wrongdoing.

"I won the popular vote if you deduct the millions of people who voted illegally," he said -- without any proof.

Upon taking office, Trump set up a short-lived commission to investigate voter fraud, though evidence was never found.

2018

Trump also warned of voter fraud ahead of the 2018 midterms, when Democrats ultimately won back control of the House of Representatives.

"Law Enforcement has been strongly notified to watch closely for any ILLEGAL VOTING which may take place in Tuesday’s Election (or Early Voting). Anyone caught will be subject to the Maximum Criminal Penalties allowed by law," he tweeted shortly before Election Day.

At least one other notable Republican jumped on board in the days after that election, with now-Florida Sen. Rick Scott sounding the alarm -- while not offering evidence -- as votes were still being tabulated in his tight race with then-Democratic Sen. Bill Nelson, whom Scott ended up unseating.

"Every Floridian should be concerned there may be rampant voter fraud in Palm Beach and Broward counties," Scott said. "I will not sit idly by while unethical liberals try to steal this election from the great people of Florida."

2020

As he did in 2016, Trump leaned into fraud allegations before his reelection bid, warning that August 2020 that "the only way we're going to lose this election is if the election is rigged."

After his defeat by Joe Biden, his claims became more frequent, with Trump swiftly leveling vocal yet baseless allegations in the early hours after Election Day. In a speech at the White House, he appeared particularly focused on ballots that were counted late into the evening, even though votes being counted late into the night is typical.

"This is a fraud on the American public. This is an embarrassment to our country. We were getting ready to win this election. Frankly, we did win this election," he said, adding, "We want all voting to stop."

On Nov. 7, 2020, as news organizations correctly projected that Biden had defeated him, Trump tweeted the opposite: “I WON THIS ELECTION, BY A LOT!” he claimed. In a statement, he vowed that "this election is far from over" and promised to pursue legal challenges. (Ultimately no such court cases affected the 2020 race.)

And in mid-December 2020, after the Electoral College had officially selected Biden as the next president, Trump continued to say the result should be overturned: "This Fake Election can no longer stand. Get moving Republicans," he tweeted.

In the years since, Trump consistently echoed similarly baseless messages about election wrongdoing on Twitter, in media interviews and in public appearances, including at a rally near the White House on Jan. 6 shortly before his supporters ransacked the Capitol.

The certification process by Congress -- which was temporarily delayed by the rioting -- showed how much the party had come around on Trump's claims, with Sen. Cruz helping lead the objections, citing the "concerns" among voters.

Trump continued discussing voter fraud after the insurrection, at times going so far as to suggest the 2020 election could be redone or that states could decertify their results.

2022

Many Republican midterm candidates, appealing to Trump’s base and often with his endorsement, have taken up the mantle of election fraud and made attacks on the validity of the 2020 result a part of their pitch to voters.

In some cases -- like with Arizona's Mark Finchem, a contender for secretary of state -- the GOP hopefuls have also levied warnings of fraud against others in their own party.

Kari Lake, Republicans' nominee in Arizona's gubernatorial race, falsely claimed on her website that irregularities occurred "on a scope and scale sufficient to have changed the outcome of 2020." Even after her own primary victory, she said her supporters just "out-voted the fraud."

Notably, in Pennsylvania, as Dr. Mehmet Oz awaited the results of his close primary win over Republican opponent David McCormick, Trump implored him on social media to "declare victory” because "it makes it much harder for them to cheat." Oz declined.

The success of candidates who, like Trump, question elections that they lose could end up speaking volumes about the strength of denialism in the politics of future cycles, one expert told ABC News.

"It remains to be seen what will happen in the midterms. Will they win? What will happen in 2024? Because if that effort doesn't ultimately produce political success, it will ultimately be abandoned," said Mary McCord, the executive director of the Institute for Constitutional Advocacy and Protection at Georgetown University.

"On the other hand," McCord said, "if enough election deniers get into the positions responsible for certifying elections … then you could have a situation where there is obstruction of the actual true vote by election deniers, which would cause a real constitutional crisis."