On the night of 9 July, the television network ABC interrupted the reality TV show The Bachelorette for some breaking news from the reality TV president. At a press conference in the White House, Donald Trump announced that the retiring Supreme Court justice Anthony Kennedy would be replaced by Brett Kavanaugh, a judge on the DC Circuit Court of Appeals.

Kennedy was considered a “swing voter” on the culture war issues that so often reach the bench. He was nominated in 1987 by a Republican president, Ronald Reagan, but wrote the court’s opinion in favour of same-sex marriage in 2015. Brett Kavanaugh is a hardline conservative who has described a ban on assault weapons as “unconstitutional”, and once wrote an opinion defending a voter ID law which opponents said disenfranchised thousands of non-white voters. He has also said that sitting presidents cannot be indicted, which must be reassuring for Trump.

Let’s be clear: the hard right is now in charge of the highest court in the land. Kavanaugh takes his seat alongside Neil Gorsuch, whom Trump appointed to the Supreme Court in April 2017, meaning that conservatives now have a solid 5-4 majority on the bench. Prepare for a rollback of progressive achievements on everything from gay rights and affirmative action to immigration reform and health care. Then there is Roe vs Wade, the 1973 judgement that ruled that a total ban on abortion violated women’s right to privacy. “You are going to see 20 states pass laws banning abortion outright,” CNN legal analyst Jeffrey Toobin declared on 28 June, the day Kennedy announced his retirement. “Just banning abortion. Because they know that there are now going to be five votes on the Supreme Court to overturn Roe vs Wade.”

The composition of the Supreme Court matters so much because its judges are appointed for life and many serve into their 70s or 80s. Even if Trump is impeached in 2019 or voted out of office in 2020, his influence on US laws and politics will now endure for decades. Gorsuch, 50, and Kavanaugh, 53, could still be writing opinions in 2048 or even 2058. That would make Trump – Trump! – the most consequential president of our lifetimes.

Isn’t it time to consider term limits? Or at least a mandatory retirement age? No other equivalent court in the Western world operates in this bizarre way. In the UK, Supreme Court justices have a mandatory retirement age of either 70 or 75 (depending on when they were appointed). The oldest US Supreme Court justice right now is the 85-year-old liberal Ruth Bader Ginsburg.

The bigger problem, though, is the naked politicisation of a court that is supposed to be above politics. Did the Founders really intend for an unelected body to wield so much power over elected politicians – and to wield it in such a transparently and brazenly partisan manner? Remember, the nine justices have the power to strike down laws as unconstitutional; to decide disputes related to the election of the president or vice-president; and to issue opinions that become binding on all the courts in the US.

In recent years, the court’s credibility has been repeatedly questioned. Take Bush vs Gore, which decided the outcome of the 2000 presidential election. Five justices – all conservatives and all appointed by Republican presidents – voted to hand the White House to Bush by refusing to allow the continued counting of votes in Florida. The 5-4 vote in Dubya’s favour divided along straight party lines.

Then there was the death of Justice Antonin Scalia, an arch-conservative, in February 2016. The Republican senate majority leader, Mitch McConnell, refused to allow Barack Obama to nominate a judge, claiming – without any real precedent – that the decision had to wait nine months, until after the presidential election that November. The Republicans effectively stole that Supreme Court vacancy from Obama and handed it to Trump.

Since then, Trump’s appointee Gorsuch has delighted conservatives by voting – as part of the majority! – in favour of racially gerrymandered election maps in Texas, the right of employers to prevent employees from filing class-action lawsuits, and Trump’s notorious “Muslim ban” on citizens from several majority-Muslim nations entering the US.

See how this works? The whole thing is a sham. In a democracy, it makes little sense to have unelected judges deciding on some of the most contentious issues in public life. It makes no sense at all when those judges are doing so on the basis of political ideology rather than legal scholarship. Throw in the fact that seven of the nine justices are white, six are men, and four (John Roberts, Samuel Alito, Gorsuch and, now, Kavanaugh) were appointed by presidents who lost the popular vote, and it is difficult to argue that the Supreme Court isn’t in dire need of reform.

The crucial role that the Supreme Court plays in US public life was perhaps best explained by Alexis de Tocqueville, in 1835. “The President may slip without the state suffering, for his duties are limited,” he wrote in Democracy in America. “Congress may slip without the Union perishing, for above Congress there is the electoral body which can change its spirit by changing its members.” However, de Tocqueville added, “if ever the Supreme Court came to be composed of rash or corrupt men, the confederation would be threatened by anarchy or civil war”.

So what happens when you have a court not just composed of rash and corrupt men but also appointed for life by the most rash and corrupt of men? The American people can’t say they weren’t warned.