With just weeks left in his final term, U.S. Sen. Pat Toomey played a key role in blocking sweeping anti-money laundering legislation that was created to choke off the billions of dirty dollars pouring into the United States from shady operators, including drug traffickers, oligarchs and corrupt foreign leaders. The outgoing Pennsylvania Republican pushed last week to halt the reforms from being included in the nation’s annual defense spending bill in a blow to advocates who had gained bipartisan support to wage the most comprehensive crackdown on money laundering in a generation. Citing the flow of suspicious money into the...