1978Final results
1978 Democratic primary for Oklahoma Senate District 20
Oklahoma State Senate · Oklahoma
John A. Heinze (D) won with 64.7% of the vote, defeating Donald C. Welch (D) by 29.3 points.
John A. HeinzeDemocrat · winner
64.7%5,486
Donald C. WelchDemocrat
35.3%2,998
8,484 votes
Source: Harvard Dataverse / Carl KlarnerUpdated Sep 30, 2026, 7:29 AM ET