They have been hailed as the conscience of the Republican party, heroes of the resistance to former US president Donald Trump’s hostile takeover.

But Senator Mitt Romney, Congresswoman Liz Cheney and others this month helped kill off a voting rights bill that Democrats say is essential to protecting democracy from a Trump-driven onslaught.

The blanket opposition from these Republicans is provoking criticism that their professed rejection of the ex-president rings hollow and, despite their lofty words, they are ultimately helping further his authoritarian agenda.

“They might not like Trump but they have the character of Trump,” said LaTosha Brown, co-founder of Black Voters Matter. “The reason why Trump was able to lead their party is because he is a good representation. He’s a liar; they lie. They’ve decided to use any means necessary to maintain power. If that means political corruption, they decide that they’re going to go that route.”

Black Voters Matter and other groups warn that Republican-led states across the country are passing laws making it more difficult for African Americans and others to vote by consolidating polling locations, requiring certain types of identification and ordering other changes.

In response Democrats in the House of Representatives last week passed the Freedom to Vote: John R Lewis Act, which would make election day a national holiday, ensure access to early voting and mail-in ballots and enable the justice department to intervene in states with a history of voter interference.

The legislation was also supported by all 50 Democrats in the Senate but collapsed this week when Republicans used a procedural rule known as the filibuster to block it in the evenly divided chamber. Chuck Schumer, the majority leader, then called on a vote on changing Senate rules to allow the chamber to pass the bill by a simple majority vote. Again all Republicans were opposed, and now they were joined by Democrats Joe Manchin of West Virginian and Kyrsten Sinema of Arizona, ensuring a 52-48 defeat.

It was a bitter defeat for Joe Biden just hours after he held a marathon press conference on Wednesday marking the end of his first year in office. “I am profoundly disappointed,” the president said in a statement.

Much liberal fury was focused on Democratic holdouts Manchin and Sinema. But their intransigence only mattered because all the Republicans – including so-called moderates – stood firm against legislation that aims to combat voter suppression, which largely impacts communities of color. Even those who claim to be fiercely anti-Trump.

Romney, a former presidential nominee, is a prime example. He was the only senator to break with his party by voting to convict Trump for abuse of power in his first impeachment trial in 2020. He was then one of seven Republicans to find Trump guilty of incitement of insurrection at his second impeachment trial last year.

“Well, I like Mitt,” Biden told reporters at the press conference lasting nearly two hours. “Look, Mitt Romney is a straight guy.”

Yet by then Romney, senator for Utah, had already spelled out his opposition to the voting rights legislation, dismissing it as a partisan takeover of federal elections and even comparing it to Trump’s false claim of election rigging in 2020.

Romney was not alone. Senator Ben Sasse of Utah, who also voted to convict Trump at last year’s impeachment trial, described the push to defend voting rights as a “charade” to satisfy a minority “addicted to rage on Twitter”, adding: “It’s bad for America. It’s just as undermining of public trust in elections as what Donald Trump did last year.”

Senators Susan Collins, Lisa Murkowski, Rob Portman and Tim Scott, all of whom have spoke out against Trump at various times, opposed the bill. In the earlier House vote, NeverTrumpers Liz Cheney and Adam Kinzinger also toed the party line.

Cheney, vice chair of the House select committee investigating the January 6 insurrection at the US Capitol, has earned bipartisan admiration from some unlikely quarters. New York Times columnist Thomas Friedman even floated the idea of her becoming Biden’s running mate in the 2024 election.

But the daughter of former vice president Dick Cheney made clear last year she did not see connection between Trump’s “big lie” about 2020 and the blitz of voter restrictions imposed by Republican state legislatures. “I will never understand the resistance, for example, to voter ID,” Cheney told Axios on HBO.

Some commentators agree that there is nothing inconsistent about decrying Trump’s assault on democracy and rejecting Democrats’ sweeping proposals.

Michael Steele, the first African American to serve as chairman of the Republican National Committee, said: “You can be against Donald Trump and have a policy view on voting rights – I would personally maybe disagree with it – that would not lead them to support the proposed legislation in the House or the Senate.”

But some conservative critics of Trump admit that the reforms, which they regard as an example of government overreach at the expense of states’ autonomy (even though article I of the constitution explicitly authorises Congress to set federal election rules), put them in a quandary.

Joe Walsh, a former Republican congressman from Illinois, said: “I am vehemently anti-Trump, but anti- what the Democrats are trying to do at the federal level, so I’d be in the same grouping. Republicans are doing a bunch of shit but the answer to that in my mind is not bad, unconstitutional federal legislation.”

But Walsh objects to Romney’s attempt to equate Trump’s lies with Biden’s policy. “I disagree with Mitt and any other Republican that’s making any sort of comparisons between what Trump did to our elections and what Democrats are doing.”

This week’s vote was also the latest marker of the Republican party’s transformation in the Trump era. Sixteen of its current senators voted to re-authorise the Voting Rights Act in 2006 but opposed the latest bill, which would update the most powerful part of the law. Republican presidents Ronald Reagan, George H W Bush and George W Bush all supported its renewal.

Antjuan Seawright, a senior adviser to the Democratic Congressional Campaign Committee, took issue with Romney and colleagues’ claim that Republicans are not making it harder for minorities to vote.

“It’s intellectually dishonest for anyone to say that there’s not an effort to suppress, suffocate and silence the votes of Black people in particular around this country. All you have to do is look at the bills that have been filed and where they have been filed,” he said.

With the voting rights measures aimed at safeguarding democracy now apparently dead in the water, it may be harder for independents, liberals and others to heap praise on anti-Trump Republicans in quite the same way as before.

Kurt Bardella, an adviser to the Democratic National Committee, argues that doing the right thing once does not make them heroes. “Just because you’re anti-Trump doesn’t mean you’re still not part of the anti-democratic effort that’s being spearheaded by the Republican party in America.”

Bardella, a former senior advisor to Republicans on the House oversight committee, added: “For Republicans like Mitt Romney and Liz Cheney, it says everything that they’re still willing to be called Republicans, and it is the Republican party’s position to make it harder for minorities in America to vote. You look at the closing of voting locations in states like Georgia, where locations that have the highest density of minority voters are now having less options to go vote.

“That’s pretty straightforward. That’s pretty racist. It demonstrates the white privilege in play for people like Mitt Romney and Liz Cheney to not see that. The reality is, if they’re not willing to move forward and assist in the effort to enact voter protections in America, then they’re Donald Trump’s biggest ally.”