When Jeremy Corbyn prepares for Prime Minister’s Questions, he does so with two audiences in mind: Labour MPs and journalists watching in the chamber, and viewers on Facebook. The first group wants to see Theresa May discomforted and the government exposed. The second group is best served with a one-minute clip that majors on the Conservatives’ familiar failings rather than anything particularly topical.

As a result, at least one of Corbyn’s six questions is designed not to elicit a response from the Prime Minister – or even to raise a particularly big cheer from his backbenchers – but to go viral on social media. It might bemuse sketch-writers to hear him outline the hardships caused by austerity when the theme of the week is Brexit, but the Facebook audience wants to hear Corbyn play one of his greatest hits.

This tactic underlines the central question of Jeremy Corbyn’s leadership: is he any good at politics? The answer is: yes and no. If success is measured in forcing government U-turns or causing embarrassment to the Prime Minister in the House of Commons, then Corbyn is bad at politics. If the aim is raising his profile online and growing the movement, then he is good at politics.

The election result came from the latter, with the Labour leader spreading his message through viral videos, campaigns and friendly television appearances. The trouble is that he now faces as many as five years in which the measure of success is the former. Despite sitting as an MP since 1983, Corbyn has little time for parliament as an institution. Neither he nor any of his staff are well versed in the procedural minutiae needed to make life difficult for a government without a majority. Added to that, because of his dislike of sacking people, underperforming shadow ministers are unlikely to be replaced.

Corbyn’s allies defend his approach by pointing out that the government has almost no agenda for this parliament, apart from Brexit legislation. Even a crack team of wonks would struggle to pick holes in the Domestic Violence Act, a law that Labour supports. Victories, they say, will come from toughening the government’s line rather than exposing its weaknesses.

Nonetheless, opportunities to expose the government’s incompetence are undoubtedly being missed. The troubled Universal Credit programme is a case in point. The government has managed to roll out a system in which payment delays have caused working families who have “done the right thing” (as the tabloids put it) to face financial shortfalls over Christmas.

This is opposition politics with the difficulty setting turned down to “easy”. Yet Debbie Abrahams, the shadow welfare secretary, has been all but invisible. Credit for the government’s U-turn – Philip Hammond announced in the Budget that waiting times would be cut by a week – therefore went to the Tory backbencher Heidi Allen.

On Brexit, Labour cannot expose the government’s muddle without revealing its own. I count at least five schools of thought among MPs, three of which are represented in Jeremy Corbyn’s inner circle. Diane Abbott, the shadow home secretary, is horrified by the anti-immigration tone of the Leave campaign and fears that the leadership risks alienating its young supporters unless it adopts a softer position. Jon Trickett, one of the MPs who nominated Corbyn as Labour leader, thinks that the referendum result demands a tougher line on migration. Corbyn is an instinctive Eurosceptic, but winning an election takes precedence. Keir Starmer – not in the inner circle but thought to be doing a good job by the leader’s office – believes that our membership of the customs union can be saved, even if Britain cannot stay in the single market.

In light of this, the only unifying Brexit position is also the one that is the least dangerous to the Conservatives: silence.

Where does that leave Labour? Many pollsters privately believe that it is almost impossible to predict voting intention, because it is ever more difficult to speak to a representative sample of the country. Polls still have their uses, however, and one of them is to reveal what voters like or dislike about the parties. The Conservatives are used to trading on their reputation for competence and economic management. If Labour does not attack them on Brexit and is ineffective at opposing welfare reforms, it has little opportunity to remove that advantage – at least until the local elections in 2018 allow Corbyn to return to his comfort zone on the campaign trail.

Yet, even if Labour is not seizing the initiative to march towards power, the party appears to be drifting in that direction. The political headwinds that Corbyn tapped into in June – increasing numbers of people unable to get on the housing ladder, a proliferation of poorly paid and insecure jobs, a sense of unease among the socially liberal about the direction of British politics – are growing stronger. Philip Hammond’s Budget achieved its first aim of stabilising his position within the government but it did nothing to arrest an economic and political trajectory that favours Labour.

There is also a cross-party consensus at Westminster that Labour will make gains from the SNP at the next general election (the most bullish forecasts put this at 25 seats). Team Corbyn are happy with the triumph of the trade unionist (and loyal left-winger) Richard Leonard in the Scottish Labour leadership and believe he will erode the SNP’s domination of Scottish politics.

To some, that analysis will seem complacent. A bad Brexit could yet reignite the desire for Scottish independence. Philip Hammond’s next Budget might be more ambitious in grappling with the economy’s structural problems. If so, Labour’s drift towards power could yet be interrupted.