In its latest chapter, the discussion has become an item on the busy agenda of the House of Representatives's Standing Committee on Social Policy and Legal Affairs.

The committee's MPs held a roundtable on Thursday about the prospect of extending the parliamentary cycle by one year and locking in the election date.

Before that, then-Labor leader Bill Shorten revived the idea, which had support from then-prime minister Malcolm Turnbull. It promptly disappeared. Kevin Rudd in 2007 promised a referendum on extended parliamentary terms, and didn't follow through.

There's no need to be cynical about this history of scattered enthusiasm. In fact, look at the players involved, and there's one reason to take the idea of fixed four-year terms seriously.

First among arguments for a four-year term and locked election dates is the shambolic instability of Commonwealth governments since Kevin Rudd won in 2007.

As the latest victim of the political death cycle set in motion for prime ministers since Mr Rudd's first demise, it seems fitting that Mr Turnbull expressed support for extended parliamentary terms.

The debate's recurring nature is a problem, because it shows the question is important enough to be raised but not taken seriously enough to be answered.

The proposal to extend parliamentary terms is an important one, and the nation needs the discussion settled. And it should be settled in favour of changing terms of federal parliament to four years, with fixed election dates.

The three-year maximum term is set by the constitution and was something decided at the beginnings of federation.

Australia's political system quickly shed the government instability that marked the 1900s as party lines formed and hardened.

Whether or not three-year maximum terms served governments in those times well, like the fluid party structures of early federation, they appear a relic of a younger, different Australia. They no longer fit today's political realities.

It's harder now for anyone governing to make decisions and reforms that are necessary but difficult to sell. A non-stop media cycle has distracted recent governments. Public debate is fracturing along ideological lines and it's harder to build consensus for change.

It goes without saying governments should have to build consensus and convince the public to accept reforms.

But it's harder to imagine leaders today achieving the kind of positive, transformative changes Bob Hawke and Paul Keating made to Australia in the 1980s. That's partly an indictment of the quality of today's MPs, but it also reflects new political realities.

Short electoral cycles undermine good decision-making by training the eyes of governments on the next poll. The new pressures of social media and the 24/7 media cycle exaggerate this weakness. It's also unfair that governments can choose election dates to their own advantage.

Supporters of four-year fixed terms will need to answer the legitimate questions of those arguing the change will water down democracy at a time Australians are quietly losing other freedoms.

Voters may choose to hold onto their right to throw governments out in three years or less.

There's a lot to say for this, considering the chaotic and anti-democratic tendencies of political leaders overseas. It's comforting to know that, should we find ourselves stuck with a bad government, it doesn't have to be for long.

A longer parliamentary term by itself won't steady Australia's politics, encourage governments to pursue long-term plans, or make it easier for them to persuade the public to accept reform.

It's still a way to prevent the instability of the last decade, and it's a change Australians should embrace.