 Over the past 50 years , Sarnia 's voters have been moderate , and the party affiliation of its Members of Parliament , both provincial and federal , has swung back and forth largely between the Liberal and Progressive Conservative parties ( a New Democrat was elected in their 1990 provincial wave ) . 
 Over the past 50 years , Sarnia <a href='null_genetive' title='1'><mark>'s</mark></a>voters have been moderate , and the party affiliation of its Members of Parliament , both provincial and federal , <a href='been_done' title='2'><mark>has</mark></a> swung back and forth largely between the Liberal and Progressive Conservative parties ( a New Democrat was elected in their 1990 provincial wave ) . 
Ova the past 50 yrs , Sarnia  voters have been moderate , and da party affiliation of its Members of Parliament , both provincial and federal , done swung bacc and forth largely between the Liberal and Progressive Conservative parties ( a New Democrat was elected in their 1990 provincial wave ) .