The picture that the top Republican painted was both vivid and terrifying. He warned that additional funding for the Internal Revenue Service would lead to armed auditors banging down front doors to squeeze hard-earned dollars from working Americans.

“Are they going to have a strike force that goes in with AK-15s already loaded, ready to shoot some small-business person in Iowa with these?” Senator Chuck Grassley said on Fox News last week.

The image conjured up by Grassley bears little resemblance to reality. Democrats have indeed directed nearly $80bn to the IRS over the next 10 years as part of their climate and healthcare spending package, the Inflation Reduction Act, which Joe Biden signed into law on Tuesday.

But Republican lawmakers have spread hyperbolic and often false information about how those funds will be used, stoking outrage among their supporters and alarming experts who say the claims could increase the risk of political violence.

Grassley is far from alone in invoking the image of gun-toting auditors. Based on a job posting for the IRS’s criminal investigations unit, which makes up only a small fraction of the agency’s employee base, prominent Republicans and conservative media figures have falsely claimed that the Democrats’ bill will arm tens of thousands of new auditors.

The Fox News host Brian Kilmeade has warned his viewers that “Joe Biden’s new army” of armed IRS agents could “hunt down and kill middle-class taxpayers that don’t pay enough”, while the chair of the Republican National Committee, Ronna McDaniel, has suggested Democrats may soon “send the IRS ‘SWAT team’ after your kids’ lemonade stand”.

Such dubious claims have even made their way onto the House floor. As the House debated the Inflation Reduction Act last Friday, far-right congresswoman Lauren Boebert equated expanding IRS resources to “committing armed robbery on Americans”.

That comment prompted a rebuke from John Yarmuth, the Democratic chair of the House budget committee.

“This is Republicans making this up to scare the American people,” Yarmuth said in response to Boebert’s remarks. “I would implore my Republican colleagues to cut out the scare tactics, quit making things up and debate the substance of this bill.”

The substance of the Inflation Reduction Act tells a far different story than the one propagated by some Republican lawmakers. The sweeping bill includes a number of provisions to bring down Americans’ healthcare costs and reduce planet-heating emissions, marking the country’s most significant effort yet to tackle the climate crisis.

The cost of the legislation is covered through a series of tax changes – including a new minimum corporate tax and a tax on companies’ purchases of their own shares – as well as enhanced IRS enforcement. The Congressional Budget Office has estimated that the additional IRS funding will bring in approximately $200bn in revenue over the next 10 years, more than covering the cost of the agency’s larger budget.

Republicans have claimed it will result in additional audits for hundreds of thousands of middle-class Americans.

“Do you make $75,000 or less? Democrats’ new army of 87,000 IRS agents will be coming for you,” the House Republican leader, Kevin McCarthy, said in a tweet last week.

The 87,000 number has been repeatedly cited by Republicans, but it is not necessarily a reflection of how IRS funds will be used. The number appears to be taken from a chart buried in a 2021 treasury department report about the need to increase the IRS budget.

But IRS leaders note that the agency has not yet outlined specific plans for how the funds will be used over the next decade, and any new employees who are hired will fill a variety of roles.

While more than half of the new IRS funds are earmarked for enforcement purposes, the agency also intends to use the money to improve its customer service and informational technology, both of which have suffered in recent years as a result of repeated budget cuts.

Between 2010 and 2018, budget decreases resulted in a 22% decline in the overall number of IRS employees, while the number of people working in enforcement roles fell by 30%.

Those staffing cuts have made it more difficult for average Americans to reach an IRS employee who might be able to answer basic questions about their tax returns. Fewer than 15,000 IRS workers handled nearly 200m calls received during the first half of 2021.

And among the revenue agents and revenue officers who handle the most complicated audits, the losses have been even more severe, with roughly 40% of those employees leaving the agency.

This appears to have benefitted America’s richest residents and largest corporations. With fewer experienced IRS staffers available to analyze complicated returns, audit rates for those groups have fallen dramatically.

Between 2010 and 2018, the percentage of audits conducted on individual tax returns showing more than $10m in annual income fell from 18.4% to 6.7%, the treasury department has said. In that same time period, corporations with assets worth over $20bn saw their audit rate fall from 98% to 49.3%.

“The impact of those budget cuts has been most helpful for high-income [people] and higher-wealth businesses and most harmful for ordinary filers that don’t have representation from lawyers or accountants,” said Chye-Ching Huang, executive director of the Tax Law Center at New York University.

Huang noted that the disproportionate decrease in audits of wealthier Americans can be partly attributed to the fact that audits of lower-income individuals are usually easier to conduct, meaning IRS employees need less training to complete them. As more experienced auditors have left the agency, audits overall have decreased, and lower-income Americans have become a larger proportion of the population receiving heightened IRS scrutiny.

“The IRS doesn’t have the resources it needs to handle the complex returns of high-wealth filers and large businesses, and this is what the [Inflation Reduction Act] is intended to reverse,” Huang said.

Indeed, Democrats have promised that the additional IRS funding will specifically be used to root out tax non-compliance among the wealthiest Americans and largest businesses. In a letter sent to the IRS commissioner last week, Treasury Secretary Janet Yellen said, “Contrary to the misinformation from opponents of this legislation, small business or households earning $400,000 per year or less will not see an increase in the chances that they are audited.”

But reassurances from the Biden administration and multiple fact-checks from reputable news organizations have not stopped Republicans from claiming that middle-class Americans should expect armed IRS agents to come knocking on their doors.

“Those IRS agents are designed to come after you. They’re not designed to come after the billionaires and the big corporations,” Republican Senator Ted Cruz told Fox News earlier this month. “They’re designed to come after small businesses and working families across this country.”

Jennifer Mercieca, a professor at Texas A&M University and historian of American political rhetoric, said Republicans’ messaging around the IRS provisions serves to obscure their own taxation objectives.

“Since they can’t come right out and say that they want low taxes for the wealthy and corporations – or, relatedly they don’t want to fund the IRS – they instead claim that average Americans’ rights are in danger,” Mercieca said.

Some Republican lawmakers have gone so far as to directly tie the increased funding for the IRS to the recent FBI search of Donald Trump’s Florida resort.

“After [today’s] raid on Mar A Lago what do you think the left plans to use those 87,000 new IRS agents for?” Republican Senator Marco Rubio said in a tweet last week.

With support for political violence on the rise in the US, experts worry that Republican leaders’ fear-mongering over the IRS funding could increase the risk of attacks against government officials. Anger over the FBI search of Mar-a-Lago has already sparked an increase in the number of threats against the bureau’s agents and offices, and one man was fatally shot last week after trying to breach the FBI’s Cincinnati office.

“What leaders say matters, and people listen to the political elites,” said Lilliana Mason, a political science professor at Johns Hopkins University and an expert on extreme partisanship.

Mason added: “Considering how many threats we’re seeing against FBI offices, it’s pretty clear that adding a new target to people who are already feeling angry and attacked and victimized is not a great idea.”

Democratic members of Congress have also tried to ring the alarm about the potential ramifications of Republicans’ criticism of the IRS budget.

“The incendiary conspiracy theories Republicans are pushing about armed IRS agents are increasingly dangerous and out of control,” the Senate finance committee chair, Ron Wyden, said last week. “It’s unbelievable that we even need to say this, but there are not going to be 87,000 armed IRS agents going door-to-door with assault weapons.”