He was defeated in Welland as a candidate of the Cooperative Commonwealth Federation in a 1950 by-election, and in the general elections of 1953, 1957 and 1958.
He challenged Progressive Conservative incumbent Ellis Morningstar for the Welland provincial constituency in the 1967 election, but lost by 260 votes.
Morningstar retired at the 1975 election, and Swart was able to defeat his successor, Allan Pietz, by 1,115 votes.
Swart had been the leading advocate of public auto insurance in Ontario in the 1980s and was especially critical of the Rae government's decision to go back on its promise to introduce the program.
Swart was considered a political mentor to Peter Kormos who inherited both his predecessor's seat in the legislature and his strong advocacy of public auto insurance.