A member of the Conservative Party of Canada, Mockler previously served two non-consecutive stints in the Legislative Assembly of New Brunswick from 1982 to 1987, and again from 1993 to 2008.

He studied at the University of Moncton where he earned a Bachelor of Arts in Political Science and Sociology and a Master of Business Administration degree.

[3] Upon his return to New Brunswick, Mockler was able to run again to be a Member of the Legislative Assembly (MLA) as Pierrette Ringuette, the Liberal who had defeated him in 1987, had been elected to the House of Commons of Canada and a by-election was being held to replace her.

In 2006, after the establishment of new electoral boundaries in New Brunswick, Mockler defeated soundly Liberal incumbent, Bert Paulin.

Mockler instead backed Belinda Stronach and served as co-chair of her campaign in New Brunswick and helped organize it in Quebec.