A pair of studies released last week indicates immigrants, both legal and undocumented, are less likely to commit crimes than their native-born U.S. counterparts. Above, demonstrators protest President Trump's travel ban in Chicago, March 16, 2017. Kamil Kraczynski/Reuters

A pair of studies indicate immigrants are less likely to commit crimes than U.S. citizens. The studies by the Sentencing Project and the Cato Institute dispute President Donald Trump’s portrayal of undocumented immigrants as a source of crime.

The fiscal 2018 budget Trump released last week gives an additional $3 billion to the Department of Homeland Security to fund his proposed border wall and executive orders on immigration.

Trump often has portrayed immigrants as a source of crime, pointing up individuals who were slain by undocumented immigrants.

Read: How Donald Trump May Be Creating Fake News About Immigrants Every Week

But the studies released last week cast doubt on the premise.

Among people 18-54 years of age, 1.53 percent of those born in the United States were behind bars, as were 0.85 percent of undocumented immigrants and 0.47 percent of legal immigrants, the Cato study indicated. In sheer numbers, that translates to 2 million U.S. born prisoners, 123,000 undocumented immigrants and 64,000 legal immigrants.

Read: Trump Says Immigrants Are Killing Everyone Even Though Data Says Otherwise

“All immigrants are less likely to be incarcerated than natives relative to their shares of the population,” the libertarian Cato Institute said. “Even Illegal immigrants are less likely to be incarcerated than native-born Americans.”

The Sentencing Project study suggested immigrants actually may have “contributed to the historic drop in crime rates” since 1990. Violent crime has dropped from 730 per 100,000 citizens in 1990 to 362 in 2014. During that same period, the number of undocumented immigrants grew from 3.5 million to 11.1 million.

“Policies that further restrict immigration are therefore not effective crime-control strategies,” the Sentencing Project study said. “These facts — supported by over 100 years of research — have misrepresented both historically and in recent political debates.

“Starting from his first day as a candidate, President Donald Trump has made demonstrably false claims associating immigrants with criminality.”

The study concludes: “False statements about immigrant criminality contribute to unfounded public fears that threaten the safety of immigrants and U.S. citizens. Improving public safety is a complicated question that cannot be addressed by scapegoating foreign-born residents but rather by investing in effective community-based solutions that address the true causes of crime.”

Rep. Raúl Grijalva, D-Ariz., told the Hill that Republicans are making a mistake by going after immigrants.

"The weakest of people in this country are the ones being made the scapegoats for everything, and unfortunately, facts don't matter, logic doesn't matter," Grijalva said.

"It's a rush to deal with a campaign issue that I think Republicans in general and the Trump administration specifically feel that an anti-immigrant strategy is going to be something that will serve them well in the next round of elections. I don't think so. I think it's going to catch up with them."