1990Final results
1990 election for California's 20th District
U.S. House · California
William Thomas (R) won with 59.8% of the vote, defeating Michael A. Thomas (D) by 25.3 points.
William ThomasRepublican · winner
59.8%112,962
Michael A. ThomasDemocrat
34.5%65,101
William H. DilbeckLibertarian
5.6%10,555
188,925 votes
Source: MIT Election Data and Science LabUpdated Sep 30, 2026, 7:25 AM ET
The seat over time
D − R margin in this seat's races around 1990
Races before and after
Source: MIT Election Data and Science LabUpdated Sep 30, 2026, 7:25 AM ET
Money in this race
Each line compares the two campaigns on one scale.
Michael A. ThomasWilliam Thomas
$695
Raised by the campaign
$430.5K
$690
Spent by the campaign
$496.8K
$15
Cash on hand
$157.4K
Campaign money: FEC, through Sep 30, 1990; FEC, through Dec 31, 1990.
Source: FEC campaign filingsUpdated Dec 31, 1990