[92] St. Louis party leader Robert E. Hannegan's support of Truman proved crucial; he later brokered the deal that put Truman on the national ticket. In the end, Stark and Milligan split the anti-Pendergast vote in the Senate Democratic primary and Truman won by a total of 8,000 votes. In the November election, Truman defeated Republican Manvel H. Davis by 51–49 percent.[93] As senator, Truman opposed both Nazi Germany and Communist Russia. Two days after Hitler invaded the Soviet Union in June 1941, he said:

.mw-parser-output .templatequote{overflow:hidden;margin:1em 0;padding:0 40px}.mw-parser-output .templatequote .templatequotecite{line-height:1.5em;text-align:left;padding-left:1.6em;margin-top:0}If we see that Germany is winning we ought to help Russia, and if Russia is winning we ought to help Germany, and that way let them kill as many as possible although I don't want to see Hitler victorious under any circumstances.[94]
This quote without its last part later became a staple in Soviet and later Russian propaganda as "evidence" of an American conspiracy to destroy the country.[95][96]

Truman Committee
Further information: Truman Committee
In late 1940, Truman traveled to various military bases. 