The Vermont senator released a detailed immigration policy proposal on Thursday, writing, "Unauthorized presence in the United States is a civil, not a criminal, offense."
He vowed to repeal existing statutes that put "border crossings on par with other forms of immigration violations, such as overstaying a visa."
South Bend, Indiana, Mayor Pete Buttigieg has suggested he'd support making illegal border crossings civil offenses, but not in cases in which "fraud is involved," a potentially key caveat.
Former Vice President Joe Biden also hasn't fully backed decriminalization of illegal border crossings, saying during a July presidential debate , "If you cross the border illegally, you should be able to be sent back.
His advisers shrugged off concerns that decriminalizing illegal border crossings may make their campaign, or those of other Democrats, seem soft on immigration.