WASHINGTON - Attorney General William Barr has authorized federal prosecutors across the U.S. to pursue “substantial allegations” of voting irregularities before the 2020 presidential election is certified, despite little evidence of fraud.READ MORE: Lawsuits filed, recount requested by Trump campaign — here’s where they standBarr’s action comes days after Democrat Joe Biden defeated President Donald Trump and raises the prospect that Trump will use the Justice Department to try to challenge the outcome.