Republican legislators in Oklahoma and Iowa have passed bills granting immunity to drivers whose vehicles strike and injure protesters in public streets.

And in Florida, Gov. Ron DeSantis signed sweeping legislation this week that toughened existing laws governing public disorder and created a harsh new level of infractions — a bill he’s called “the strongest anti-looting, anti-rioting, pro-law-enforcement piece of legislation in the country.”

The measures are part of a wave of new anti-protest legislation, sponsored and supported by Republicans, in the 11 months since Black Lives Matter protests swept the country following the death of George Floyd. The Minneapolis police officer who killed Mr. Floyd, Derek Chauvin, was convicted on Tuesday on murder and manslaughter charges, a cathartic end to weeks of tension.

Some, like Mr. DeSantis, are labeling them “anti-riot” bills, conflating the right to peaceful protest with the rioting and looting that sometimes resulted from such protests.

The laws carry forward the hyperbolic message Republicans have been pushing in the 11 months since Black Lives Matter protests against racial injustice swept the country: that Democrats are tolerant of violent and criminal actions from those who protest against racial injustice. And the legislation underscores the extent to which support for law enforcement personnel and opposition to protests have become part of the bedrock of G.O.P. orthodoxy and a likely pillar of the platform the party will take into next year’s midterms.

“This is consistent with the general trend of legislators’ responding to powerful and persuasive protests by seeking to silence them rather than engaging with the message of the protests,” said Vera Eidelman, a lawyer at the American Civil Liberties Union. “If anything, the lesson from the last year, and decades, is not that we need to give more tools to police and prosecutors, it’s that they abuse the tools they already have.”

Most of the protests held across Florida last summer were also peaceful, though a few in Miami, Tampa and Jacksonville produced some episodes of violence, including the burning of a police car and a sporting goods store. Still, as they embraced the bill that Mr. DeSantis signed into law, Republican leaders expressed scorn for cities that trim police budgets and tolerate protesters who disrupt business and traffic.

“We weren’t going to allow Florida to become Seattle,” said Chris Sprowls, a Republican who is the speaker of the Florida House, mentioning cities where protests lasted for months last year and demonstrators frequently clashed with the police. “We were not going to allow Florida to become Portland.”

The Florida law imposes harsher penalties for existing public disorder crimes, turning misdemeanor offenses into felonies, creating new felony offenses and preventing defendants from being released on bail until they have appeared before a judge. A survey conducted in January by Ryan D. Tyson, a Republican pollster, found broad support in the state for harsher penalties against protesters “who damage personal and business property or assault law enforcement.”

But the law goes farther. If a local government chooses to decrease its law enforcement budget — to “defund the police,” as Mr. DeSantis put it — the measure provides a new mechanism for a prosecutor or a city or county commissioner to appeal the reduction to the state.

The law also increases penalties for taking down monuments, including Confederate ones, making the offense a second-degree felony punishable by up to 15 years in prison. It makes it easier for anyone who injures a protester, such as by driving into a crowd, to escape civil liability.

So far, three bills aimed at limiting protests have been signed into law — Florida’s and new laws in Arkansas and Kansas that target protesters who seek to disrupt oil pipelines. Others are likely to come soon.

Dr. Crutcher said she was convinced that if Mr. Stitt signed the legislation, it would be applied in harsher terms against those protesting racial injustice than for white protesters demonstrating for gun rights or against abortion.

“We all know that over the last four years that we saw white supremacy, bigotry and racism show its ugly head in so many forms,” said Dr. Crutcher, who quit her job as an orthopedist to work for racial justice after the death of her brother. “This is the continuation of the Trump administration that showed us every day that Black lives didn’t matter.”

While Republican lawmakers present the anti-protest legislation as support for the police, law enforcement agencies don’t necessarily back the new proposals.