The midterm elections in the United States of America on Tuesday (6 November) will primarily determine the constitution of the Senate and the House of Representatives at a critical juncture ~ when Donald Trump’s approval rating has plummeted considerably and on a welter of issues. Viewed through that rather unnerving prism, these elections ~ intended to address the legislative dichotomy ~ are more important than any in recent memory.

This is the irony of Trumpist policies and electoral dynamics, a fact that places a huge responsibility on the shoulders of US voters on Tuesday. Only a Democratic Congress will be in a position to rein in the impulsive President Trump and his relentless campaign of hate almost as a matter of policy. Nonetheless, the midterms have not been reckoned as a referendum on Trump’s rule, to summon current jargon.

A predominantly Republican Congress will not ipso facto burnish his reputation; there are occasional rumblings of disapproval within. There is little doubt that two ugly incidents over the past fortnight have further tarnished the President’s record ~ a Trump supporter sent bombs to several Democrats and a white “supremacist” committed the most heinous act of anti-Semitic violence in the country’s history.

As things stand 24 hours before the first vote is cast, the Democrats are scarcely confident of triumph, however. Discernible is the dense cloud over the elections. American politics has become toxic. The faith of the average American in the country’s libertarian institutions has been shaken for good measure, and going by President Trump’s record over the past two years, he cannot evade responsibility for having precipitated the general decline as a matter of conscious policy.

Hence the increasingly cynical perception that he seeks consistently to be the “President of some of the United States, not of the country as a whole”. No less cynical is the barb that he is a “President without precedent”. Those who do not support or agree with him are almost invariably greeted with hate and scorn. He is acutely aware that his detractors are legion. No one denies that the US democracy is strong, but a jolt and a dent cannot be ruled out exactly two years after Election 2016.

The Democrats do have a strong case for recapturing the House of Representatives from its dishonest and sycophantic rightwing Republican leadership. That control would constrain President Trump by investigating issues that have been deliberately ignored by the current House leadership. Democratic control of the Senate is generally rated as a long shot; should it materialise, it would clip his wings further still.

It is a quirk of US politics that Democratic failure this week, by contrast, would be almost an electoral endorsement of Mr Trump. By any reckoning, this is a pivotal election for Americans, for American democracy, and for the rest of the world. Will Democrats seize the moment today (6 November)? Americans don’t have an answer.