Five days after the most tragic, appalling and cataclysmic event in modern American political history, it’s hard to know what to do next. For Clinton supporters, for liberals, for people of colour, it has been like waking up to a nightmare that not only never ends, but gets worse each day, as the consequences of a Trump presidency come into focus.

Trump will appoint the next supreme court justice and maybe several more. Doing so will ensure that the conservative bloc on the court is likely to remain a majority for a generation to come. Obamacare is likely to be repealed; Medicaid, the health care programme for low-income Americans, will be gutted, along with the social safety net; climate change will be ignored; and the mass deportation of undocumented immigrants is likely to happen in the future.

With the Republican party controlling the White House, the Senate, the House of Representatives and a majority of state houses around the country, there is precious little that Democrats and progressives can do to stop Trump and his party.

Indeed, the only institutional force standing in the way of this apocalyptic turn of events are the 46 members of the Democratic caucus in the Senate. For this group, there will be an enormous burden to hold back the conservative tide. They do have one weapon at their disposal – the filibuster. Indeed, for the first two years of Obama’s presidency, 40 Senate Republicans in a body of 100 were able to block his domestic agenda. For Democrats, however, their job will be trickier.

To begin with, there are plenty of Democratic senators who are up for tough re-election fights in 2018 in Republican states, and will be less inclined to man the barricades against Trump. But the bigger problem is that Republicans have shown little unwillingness to violate long-standing governing norms. Nothing stops Republicans from scrapping the Senate filibuster, thus ensuring that they need only a 50-vote majority to pass their agenda. They can also use a tool called the budget reconciliation process, which cannot be filibustered, to eviscerate Obamacare, cut taxes and slash the social safety net.

This will put particular pressure on Democrats to use the filibuster judiciously. Blocking a Trump pick for the supreme court is probably not on the cards. Stopping full repeal of Obamacare or undermining efforts to privatise Medicare, the healthcare programme for old people, should be higher on the agenda. But ultimately, they can block only so much and won’t be able to use their position, for example, to stop Trump from initiating mass deportations or blocking entry to all Muslims.

And it must be said that if Trump is willing to work with them on policies like infrastructure spending they shouldn’t hesitate to do so. Many Americans will suffer under Trump, but blocking measures that can help working-class Americans – even those who didn’t vote Democratic – is not what Democrats should be doing.

Much more, however, will depend on what Democrats can do outside Washington. Already there have been scattered protests in major cities in response to the election result. This is a good start. Considering Trump’s use of openly racist, nativist, misogynistic and antisemitic rhetoric on the campaign trail, and his abject refusal to apologise for it, these protests will be a necessary tool in creating solidarity among progressives and building enthusiasm for the incredibly difficult work that lays ahead. It will also be an important sign to people of colour and other vulnerable populations that Trumpism does not represent all Americans.

From a political perspective it’s highly unlikely that, no matter how disastrous a Trump presidency ends up being, Democrats will be able to take back either the Senate or the House of Representatives. Thus Democrats will need to focus intently on state and local races. This means not just gubernatorial races, but also state legislature fights. For years, Democrats disregarded these races and it’s high time they began paying more attention.

Last, they cannot forget that even though Trump will be sleeping in the White House, America remains a Democratic nation. Hillary Clinton will almost certainly end up winning the popular vote, perhaps by more than a million votes. That means that a majority of Americans will have voted for her vision of a multicultural America, not Trump’s vision of a white nationalist one.

Nonetheless, there will be calls for Democrats to put aside that vision and seek to win over the white working-class voters who came out in droves and gave Trump the presidency. It’s not a bad strategy but there are limits to it. After all, the future of America remains a liberal, multicultural one. The electorate is still getting browner and more liberal. Millennials, those between the ages of 18-29, are the most liberal demographic in America. They largely rejected Trump’s vision and cultivating them will be paramount for the Democrats.

But above all, Democrats must do what they’ve always done – serve as a voice of economic and social justice in America. Trump and his conservative cohorts will overreach. They will push through legislation like privatising Medicare and cutting the social safety net that appeals to conservative dogma but not to the broad swath of Americans – even those who voted for Trump.

In other words, Democrats must do what’s right not because it’s what they are supposed to do as Democrats, but because it’s the smartest political weapon they have. Revulsion about Trump and the excesses of a Republican Congress are the single most effective tool Democrats have to win back the Congress and the White House.

Make no mistake: the next four years in America will be singularly awful. Trumpism will rip into the American welfare state and cause untold suffering, both here and abroad. The Democratic party – and American progressives who find a home under their party banner – is the only bulwark against it. That battle will not be easy, but it must be won.

Michael Cohen is the author of American Maelstrom: The 1968 Election and the Politics of Division