To the victor the spoils. To the loser, well, just a few limp leftover dreams curling up at the edges. A Labour leadership contest is catnip for the converted; but it barely figures in the larger panorama of issues currently facing Britain. Even the Liberal Democrat contest has niche appeal; but after Thursday this is a third-order subject at best. What matters after the election is now overwhelmingly the shape and direction of the Conservative government. David Cameron’s team are the only premier league players on the pitch at this moment, along with newly promoted Nicola Sturgeon. Compared with them, the abruptly relegated may-bes and might-have-beens such as Chuka Umunna, Liz Kendall or Tim Farron barely matter at this stage.

Mr Cameron now heads a different kind of government operating in a changed political arena. The prime minister has more power than before, in that he rules alone with his Tory majority. But he has less defence against his party critics because he can no longer hide behind the Lib Dems. Mr Cameron’s planned departure from office during this parliament will also become a weakening factor, slowly draining authority and emboldening those who want to succeed him. The success or failure of the new cabinet, membership of which has begun to emerge over the weekend, will therefore hinge upon whether Mr Cameron can define a coherent and popular Conservative project and pursue it effectively, before Tory minds turn to the post-Cameron future.

This is considerably more easily said than done. First-term Mr Cameron quickly became more tactician than strategist. This time around he has not yet revealed much of his governmental hand, save to make a statesmanlike one-nation speech in Downing Street on Friday in which he promised to govern with respect. What this means in practice is not yet clear. But the change from coalition to single-party government is a big one. Its consequences have not yet been fully grasped. Policies that excited the party grassroots in the first term – like the Europe referendum, scrapping human rights laws, English votes for English laws and slashing the welfare budget – were all good for party morale when the constraints of coalition meant the government could not pursue all of them full-throatedly. But the Conservatives have the votes now. They must decide whether and how far to push that kind of agenda. This is a big call for Mr Cameron.

Michael Gove’s appointment as the new justice secretary is a good example of the dilemmas. Mr Gove is clever but divisive. He sometimes leaps before he looks. He has a talent for giving offence. It is why he was moved from education in 2014. Now he comes to a Ministry of Justice in which the judges, the lawyers and those responsible for penal policy have been bruised by his reactionary and ideological predecessor, Chris Grayling. The lawyers are not popular interest groups. But the public cares about the rule of law and, though it may not love lawyers, it cares about obeying the rules on human rights too. It may dislike the European court of human rights but it could also be uneasy about a dismissive British attitude to the court that Vladimir Putin feels able to emulate. Mr Gove must learn the meaning of governing with respect. It is a big test for him.

The prime minister’s first bunch of cabinet appointments suggests a failure to see what has changed. George Osborne, Theresa May, Philip Hammond and Michael Fallon have all been reconfirmed in their old jobs. Now Iain Duncan Smith is to stay at work and pensions too. This may seem statesmanlike and collegiate to Mr Cameron, but it implies he sees this second government as a continuation of the first. This does not square with new realities. Mr Cameron may regret not being bolder, clearer and more decisive.

Mr Cameron’s reshuffle involves higher stakes than it may seem. His majority is now in the 10s not the 70s. He can no longer blame his failures or difficulties on the limitations of coalition. And his own shelf life is limited. There is an echo of Michael Dobbs’s original House of Cards here, in which the new Tory prime minister is elected with a small majority and makes no changes to his team. At this point, Francis Urquhart begins to undermine him. Mr Cameron should remember that there will be a real-life Francis Urquhart out there somewhere.