So, Prime Minister Justin Trudeau has announced he's not keeping his definitive promise that 2015 would be the last election fought on the first-past-the-post electoral system.

These things happen.

I worked for a government that promised to reform the Senate and I personally believed in that promise. In the end, we failed.

But there's something about electoral reformers — almost a religious fervour in your beliefs — that makes it hard for you guys to deal with political setbacks.I know a lot of you — you do really care about the country's future and its politics. You want politics to be less confrontational, less partisan, less irrational, less, well, political.

Members of the House of Commons special committee on electoral reform recommended the Trudeau government design a new proportional voting system and hold a national referendum to gauge how much Canadians would support it. (Fred Chartrand/The Canadian Press)

You think politics can reach our highest human aspirations and not be limited by our lowest impulses and you really don't get why everyone else isn't as concerned as you are. And so, a week after Trudeau's announcement, there are still news stories and online outrage saying Trudeau lied or Trudeau broke faith with electoral reformers.

Grassroots groups of electoral reformers are trying to figure out what to do next. They finally saw a prime minister elected on a platform of electoral reform, and now he's abandoned the cause.

You guys thought it would be easy — that Trudeau would be different, and you could just sit back and watch him change the country for the better. But darn it, politics got in the way again.

Let me offer you some advice.

A system that resists change

There are very few Canadians who really, really think that changing our electoral system is the number one issue facing the country. You're marginalized, you're trying to change a system that resists change. But don't lose hope, there is a path forward.

Take a page from the legal firearms owners of the country.

Back in 1993, the Chrétien government introduced Bill C-68, to force firearms owners to register their long guns by January 2003. The long gun registry was a poorly designed, poorly implemented program that attacked the small community of legal gun owners by whipping up mistrust and prejudice among urban voters.

Canada's legal firearms owners could have rolled over and just accepted Chrétien's pandering to the core of his electoral coalition. After all, there aren't many firearms owners in Canada. Most are hunters, farmers and ranchers. A few are collectors. But most live in remote, rural areas. Most are strong individualists and hard to organize politically.

Ian Brodie says first past the post is the ideal electoral system for a small group of committed activists and they should take advantage. (CBC)

But thanks to the energetic efforts of a few activists, legal firearms owners organized themselves politically and got heard — loud and clear.

They found allies in the Reform Party, which stood up for their views on Parliament Hill and across Canada. In the end, Chrétien had to allow eight Liberal backbenchers to vote against the bill in an effort to save their rural seats. But by 2006, firearms owners in five of those seats defeated even those backbenchers — putting the Liberals on the path to defeat. Eventually, the Harper Conservatives repealed the firearms registry and destroyed the data that had been collected for it.

Firearms activists showed how a small but determined group can win what they want in our political system.

My advice to electoral reformers?

Visit the firearms groups and ask for their advice. Get your people organized. Print up lawn signs — drive around rural eastern Ontario and count the number of fading, rusted STOP C-68 signs you see in farmyards. Find allies in one of the opposition parties — maybe the NDP, maybe the Greens. Visit every candidate running for that party's nomination in the next election.

Get them to commit to electoral reform and make it clear you won't forgive them if they don't deliver. Then use your phone lists, your email newsletters and every technique you can to turn out your supporters and show you mean business.

Justin Trudeau announced his promise to change Canada's first-past-the-post electoral system less than two months before an election campaign saw him win a majority government. (Sean Kilpatrick/Canadian Press)

Make sure everyone in that party understands the role you played in their success. Don't let Liberals who say they support your cause off the hook. Play tough. Play the long game.

You might not like the political side of politics, but politics will always be political. Get good at it.

Senate reformers thought they could elect a Senate reformer as prime minister and then sit back and watch him change the system They were wrong. The Senate reformers got caught up in other issues — even the Senate reformer in chief.

Senate reform started to look hard. Senate reformers worried they didn't have the numbers to make a difference. So they gave up.

Small votes, big change

Here's the really great thing about first past the post:

You only have to shift a small number of votes to produce a big change in the House of Commons.

Because first past the post exaggerates the strength of the first place party, you only need to move a few thousand people to defeat a lot of MPs and elect a new government. That's harder to do with proportional representation, since a shift of a few thousand votes only defeats a few MPs. If not much changes from election to election, power rarely changes hands.

The more proportional the electoral system, the more permanent the government.

Here's the bottom line:

Take advantage of the way first past the post distorts our elections. It's the ideal electoral system for a small group of committed activists like you. Punish the parties that abandon you, just like firearms owners did a decade ago.

Use the electoral system you despise to kill off the electoral system you despise.

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