Since Donald Trump won the Republican presidential nomination, a question hangs over the Right: should the GOP survive or is it morally corrupted and politically deformed to such an extent that those of good conscience on the Centre Right must start anew? Having engaged in the original sin, if you will, of supporting Trump and then defending his aberrant presidency and helping thereby to define political deviancy down — as the late Daniel Patrick Moynihan described the decline of social and behavioural norms in his lifetime — has the GOP in essence forfeited political legitimacy permanently? There are several aspects to the question that deserve attention.

First, keep in mind the distinction between “should” (normative) versus can (capacity). The former, should the GOP survive, goes to the moral culpability of those who lifted Trump to power and kept him there. They elevated a very dangerous man who has done and continues to do great damage to our country. They have in essence lost legitimacy as a constructive force; the Centre Right cannot fully purge the stain of Trump unless it sheds or shreds the skin of the GOP. Given the enormity of the GOP’s malfeasance, a new party may in fact be required.

Then there is the more practical question: can the GOP survive? Given how toxic the GOP brand has become, the time and cost of rehabilitating the brand may not be worth it. Alternatively, anti-Trump Republicans may conclude that the financial, legal and organisational burden of creating a new party with new state parties may be crippling.

We think a middle ground makes sense. An accountability project — maybe not quite at the level of reconciliation processes in the wake of fallen regimes in South Africa or Chile — certainly is needed; a turnover in leadership is essential. The party must repudiate Trump and the Trump era to go forward. Those intent on turning away from the Trump era will require visible symbols underscoring the party’s repudiation of Trumpism, including perhaps a name change. The New Republican Party? The Modern Republican Party?

Second, is such a dramatic break really needed? Yes, if, as #NeverTrump and #NoLongerTrump Republicans believe, the Trump problem is of an entirely different magnitude than, say, Watergate, and has resulted in much more serious, permanent damage to our democracy, then it is not enough to simply shuffle the presidential candidates, make some speeches and keep the platform and leadership essentially unchanged. And yes, most of the Republicans in the House and Senate at present need to go. They have put party over country, not lived up to their oaths of office and contributed to the polarisation of our politics and erosion of our democratic norms. A clean, dramatic break is mandatory.

Third, both the specific agenda — a creaky façade left over from the 1980s — and the central values of the party are in need of revamping. Its positions on tax, budget, environmental, law enforcement and immigration policy are outmoded, counterproductive and in many cases not based on reality. That does not mean Republicans should copy Democrats. A second party with alternative views remains critical in a robust democracy. We need a party that favours market-based solutions where possible; cares about fiscal sanity; sees advantages in federalism; embraces a positive, essential role for government but is wary of highly centralised bureaucracy; and supports American leadership in defence of the international, liberal order. By the way, it is always possible the Democratic Party in its existing form goes in that direction while the far Left goes the full socialist route.

Fourth, Trump’s presidency should prompt centre-right voters and leaders to redefine the purpose, foundational beliefs and role of the party. Civic character and dedication to democratic norms, as opposed to positions on a laundry list of issues, must be elevated in importance. The party needs to return to a mediating and moderating role whereby it weeds out the most extreme and most irresponsible elements. Yes, here come the superdelegates. The party needs to resume a role of gatekeeper — a goal furthered by diverting resources back to national and state parties and away from special-interest cliques and billionaire candidates and donors. Moreover, a party that believes in a strong role for civil society must dedicate itself to repairing frayed communal ties and institutions and ending rigid tribalism.

Fifth, how Republicans behave from here on out will play a huge role in determining the extent of the housecleaning/destruction of the GOP required. It makes all the difference in the world whether Democrats, by winning elections, save the country from Trump or whether the GOP — by impeachment, support for prosecution, primary challenge — takes matters into its own hands to expunge Trump. The latter would not erase entirely the original sin they committed when they backed him, but a Republican revolt against Trump, finally, would suggest internal reformation is possible.

Republicans in office, running for office, in think-tanks and other right-wing groups should think long and hard about how they want the Trump presidency to end; it will become the defining event in their personal and political legacies. And the manner of Trump’s political demise will largely determine whether the 2016 election was the last to produce a Republican president.