Because PAlabama is every bit as red as TX or IN.
Pennsylvania's top corporate income tax rate of 9.99% is one of the highest in the U.S. -- higher even than Marxist sh!t-holes like California (8.84%), Massachusetts (8.00%) and and New York (6.5%).
Pennsylvania didn't just lose all those industries over the years because companies fled to foreign countries. They lost them because companies fled to other U.S. states. The government of Pennsylvania chased all of those jobs away.