The Edmonton Tory, who announced this week he will not seek re-election, was often the government's key attacker in the parliamentary committees he sat on. With a suffer-no-fools style, he would question the credibility of witnesses and correct what he saw as mistakes in the public record.
But as he looks towards retirement, Hawn says he's concerned about a general decline of civility in Parliament over the eight years he's been in Ottawa.
"It's no secret, obviously Parliament has been combative," said the 66-year-old former lieutenant-colonel in the Royal Canadian Air Force. "Parliament's always combative and it should be that way. But it should be measured, it should be respectful, it should be rational.
"I think we've gotten away from that, to a greater extent than I would like."
Other MPs and leaders, from one-time Reform party leader Preston Manning to the late NDP leader Jack Layton have made similar observations over the years. Three successive minority governments from 2004 to 2011 seemed only to sharpen the tone around Parliament Hill.
Prime Minister Stephen Harper and his office were criticized last month when they did not invite opposition MPs on a trip to Ukraine, saying they did not deserve to be included.
Hawn was one of a number MPs who refused to mail out a pamphlet attacking Liberal Leader Justin Trudeau to his constituents last year.
Hawn doesn't lay the blame for the lack of civility on any particular party, or expect any particular leader to produce a solution.
"I think it does come down to individuals thinking about what they're doing and saying every day and just the simple things. People fire a shot, a nasty shot, instead of just saying, 'Well you know what, maybe they've got some good ideas'," said Hawn.
"I've always said, the opposition aren't stupid people, we're all here for the same reason, they all came to Ottawa to make a positive difference and we all want to get essentially to the same destination ... we argue about the road we're on to get there."
Behind the scenes, Hawn says there has actually been decent camaraderie among MPs of different stripes, but question period isn't the best place to detect that.
"I can say that in the veterans affairs committee we do have good discussions and we don't all read from talking points ...
"It is very free-flowing and we do have good co-operation across the floor."
Hawn says he feels serene about his decision to leave federal politics, just as he did after he decided to leave the military. He is awaiting the birth this month of his second grandchild.
"The best part of the job is the people and the worst part of the job is the people," says Hawn.
"Dealing with constituents and being able to solve local problems for constituents, that feels good — when you get stopped on the street and somebody says out of the blue, 'Hey, thanks very much for fixing my problem or for doing a good job'."
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