Look no further than the past seven days to see why it’s said that a week is a long time in politics.

After heading into this final week of Parliament as a Dead Man Walking, Prime Minister Malcolm Turnbull got a new lease on political life with a slight upturn in Newspoll, as well as an Ipsos poll that warned his detractors against pursuing another leadership change.

The overwhelming ‘yes’ vote in the House of Representatives for the marriage equality bill at the week’s end was another plus for Mr Turnbull, whose opponents had hoped to hobble both him and the bill with a litany of demands for religious and other protections.

It should never be forgotten that the same-sex marriage survey was based on a warped morality that gave all voters a say whether members of the LGBTI community were entitled to be treated equally. In so doing, the survey campaign inflicted immeasurable hurt on that community.

The only good thing to emerge from the survey was that it emboldened supportive Coalition MPs to stand up to their reactionary colleagues where it really mattered – on the floor of the Parliament.

It’s worth noting that while many of his conservative colleagues dashed out the door when it came time to vote on the bill, Peter Dutton stayed in the chamber to vote ‘yes’ in accordance with the wishes of his electorate.

So even if Mr Turnbull’s cabinet ministers were implacably and very publicly split on marriage equality and “related” religious protections, the PM still ended the week with a win on the issue and one of the key contenders for his job still cleaved to his side.

Take that, Tony Abbott.

A similar about-face in fortune occurred this week for Opposition Leader Bill Shorten, who’d held the political upper hand for most of the time since the federal election in July 2016.

The Labor leader took a hit when his close supporter, Senator Sam Dastyari, was exposed as having further dodgy dealings with a Chinese benefactor.

Having secured Senator Dastyari’s resignation from a couple of low-level leadership roles, Mr Shorten’s credibility would have survived the accusations that flew from both the government and the media that he’d gone soft on the senator for factional reasons.

Far greater damage occurred, however, from the revelation that Labor’s supposedly watertight citizenship-checking processes had sprung a leak. Or five.

For months, the Labor leader had unequivocally expressed confidence that none of his party’s MPs was a dual citizen at the time of nomination for the 2016 election.

This week we learned that at least a handful of those Labor MPs had either not realised they were dual citizens, not relinquished their dual citizenship, or not received confirmation of doing so by the time they ticked the box on the application form.

Either Mr Shorten had been misled by his party officials, or he has been telling porkies in a game of brinksmanship with Mr Turnbull (and the Abbott camp, which had been hoping to bring on a leadership challenge this week).

According to various opinion polls, voters are already wary of Mr Shorten. It’s true they might elect an opposition leader who is unpopular and uninspiring, but they’re less likely to vote for a leader they don’t trust.

However, neither Mr Shorten nor Mr Turnbull deserves our respect let alone our trust after their bad behaviour this week on citizenship matters.

After losing a bevy of Coalition MPs to the High Court’s black-letter interpretation of the Constitution, the PM copied Mr Shorten’s now discredited stonewalling tactic by refusing to concede that any (further government) MPs should be referred following the public declaration of their citizenship details.

And having been sprung as a fibber on the eligibility of his own people, Mr Shorten tried to rush through a motion to refer nine MPs including his own to the High Court while the government was down two votes.

This was four months after the Labor leader refused a similar job-lot offer from the Prime Minister to quickly resolve the matter.

Between the stupid shenanigans over marriage equality, and the silly games on citizenship, it’s no wonder voters are fed up to the back teeth with politics as we know it.

Despite the swinging changes in their fortunes, Mr Shorten and Mr Turnbull ended this week clambering over each other to claim kudos that neither deserved for the long overdue legalisation of gay marriage.

In another weeks’ time the wheel of fortune will spin again, leaving one standing victorious once the votes are counted in the Bennelong by-election.

What will happen after that? Who knows? The only thing we can know for sure is that it would be foolish to predict how either man’s fortunes will unfold in 2018.