Asked this once already yesterday. What did president Truman mean when he claimed that McCarthy was an "asset" to the Kremlin?

Senator Joseph McCarthy was a Republican. Truman was a Democrat. Durring their time as seated elected officials, America was on guard and quite paranoid about the posibility of communist spies and sympathizers. McCarthy exploited the fear many felt for selfish political gain. He criticized Trumans foriegn policy, saying that officials were harboring communists. Truman fired back by saying, "The greatest asset the Kremlin has, is Senator McCarthy." Because of political mudslinging, bipartizan foriegn policy suffered. That made our nation weaker and more vulnerable