 After a sedate election that the Liberals won by a slightly reduced majority , Sifton announced his resignation as Premier to enter federal politics . Sifton 's 1917 victory would be the Liberals ' last : his successor , Charles Stewart , would lose the 1921 election to the newly @-@ political UFA . In Thomas 's estimation , Sifton would have faced a similar fate in 1917 if the UFA had run candidates then . 
