WASHINGTON - A "new normal" is emerging for the U.S. jobs market, and a growing number of economists warn that it's likely to mean that unemployment will remain persistently high, at 7 percent or more, for years to come. The 9.1 percent unemployment rate reported in May remains high by post-World War II standards long after the economy resumed growth following the worst recession in 70 years. It's prompting economists to rethink basic assumptions about the U.S. labor market.