Commentary With the record number of illegal immigrants allowed into the United States, there is a growing number of hardened criminals who were already convicted of violent crimes prior to their arrival here. Tens of thousands of such foreigners have crossed the southern border from Mexico in recent years, according to Customs and Border Protection (CBP) statistics, with a notable acceleration during President Joe Biden’s first year in office. U.S. border officials track the number of people who cross the border illegally, and who have a findable criminal record, either in the U.S. or in a country that shares its information. During President Obama’s last year in office, the number of illegal immigrants arrested at the border with a known criminal record was 12,842. Under President Trump, the number steadily declined. His first year, 2018, the number was cut by one-third to 8,531. Even as Trump opponents and open-border advocates …