When Frederick died in 1917, D.C. became the sole proprietor of the company. Between 1920 and 1922, he actively campaigned using vitriolic rhetoric against one of the two M.P.s for Dundee, then Liberal politician Winston Churchill. At one meeting, Churchill was able to speak for only 40 minutes when he was barracked by a section of the audience. At the General Election of 1922 both of the local newspapers owned by Thomson, the Liberal supporting "Dundee Advertiser" and the Conservative inlined "Courier" advised their readers to reject Churchill. Subsequently, Churchill came only fourth in the poll and lost his seat at Dundee to prohibitionist, Edwin Scrymgeour, quipping later that he left Dundee ""without an office, without a seat, without a party and without an appendix"". Thomson barred Churchill's name from his newspapers until World War II made occasional use of it unavoidable.