Ari Berman’s new book is a rich history of America’s ambivalent attitude toward majority rule. The founding document declared “all men are created equal”, but by the time a constitution was drafted 11 years later, there was already a severe backlash to that revolutionary assertion.

To prevent the union from disintegrating, free states and big states repeatedly gave in to slave states and small states, producing a constitution that would be adopted by the majority.

The first and worst decision was to give each state two senators regardless of population. Virginia had 12 times the population of Delaware. Today, the situation is vastly worse: California is 63 times bigger than Wyoming. By 2040, Berman writes, “roughly 70% of Americans will live in 15 states with 30 senators, while the other 30%, who are whiter, older and more rural … will elect 70 senators”.

The filibuster, a delaying tactic that led to most legislation requiring 60 votes to pass the Senate – but which has no basis in the constitution – makes the country even more undemocratic. Forty Republican senators representing just 21% of the population have blocked bills on abortion rights, voting rights and gun control supported by big majorities.

The House of Representatives was supposed to be closer to the people than the Senate, which wasn’t even elected by voters when first created. But when the free states placated the slave states by allowing them to count every enslaved Black person as three-fifths of a human being, for the purposes of representation, that increased how many representatives slave states sent to the House.

To Berman, it was “a fundamental contradiction that the nation’s most important democratic document was intended to make the country less democratic”. As the New Yorker Melancton Smith noted at the time, the constitution represented a “transfer of power from the many to the few”.

The national voting rights correspondent for Mother Jones, Berman also offers a horrific description of the hundreds of millions of dollars being spent by modern-day oligarchs to make America even more undemocratic. In just six years, the Federalist Society raised an astonishing $580m “through a shadowy network of a dozen dark money nonprofit groups” to put its “preferred judges on the bench”. The society has gotten a huge bang for its buck – more than 500 judges appointed by both Bushes and 226 appointed by Donald Trump were endorsed by the Federalists.

The worst results of this hammerlock on judicial appointments are at the very top of the pyramid: “For the first time in US history, five of six conservative justices on the supreme court have been appointed by Republican presidents who initially lost the popular vote and confirmed by senators representing a minority of Americans.”

And what is the “signature project” of these justices? The dismantling of the civil rights laws that are the greatest legacy of the 1960s.

Federalist Society judges worked in lockstep with the Republican Senate leader, Mitch McConnell, whose priority has been to end all effective limits on who can spend how much in every election.

“I never would have been able to win my race if there had been a limit on the amount of money I could raise and spend,” McConnell wrote of his first race, in 1984. Eighteen years later, the Republican John McCain and Democrat Russ Feingold managed to ban unlimited donations. Their law survived McConnell’s first lawsuit to undo it, on a 5-4 supreme court vote. But four years later, after the extremist Samuel Alito replaced the moderate Sandra Day O’Connor, the court gutted the law, allowing unlimited corporate expenditure as long as ads “didn’t explicitly” endorse a candidate.

“Thus began a trend,” Berman explains. “GOP-appointed judges reliably supported Republican efforts to tilt the rules and institutions of democracy in their favor … which in turn helped Republicans win more elections and appoint more judges, with one undemocratic feature of the system augmenting the other.”

As the country’s founders adopted a constitution that disenfranchised all Black people and all women, modern conservatives do all they can to keep the voting rolls as unrepresentative as possible, particularly as people of color become the majority in the US. Racism remains the strongest fuel for efforts to make it as hard as possible for Black and younger voters to exercise their franchise.

The worst recent example of this was the failure of a narrowly Democratic Senate to adopt a voting rights act in 2021. It failed when Kyrsten Sinema of Arizona and Joe Manchin of West Virginia, both Democrats then, refused to alter the filibuster rule. Manchin supported the bill, then reversed with a specious explanation: while the right to vote was “fundamental to American democracy … protecting that right … should never be done in a partisan manner”

Berman’s book ends on a more hopeful note, with descriptions of Democratic victories in Michigan and Wisconsin.

In Michigan, a 29-year-old activist, Katie Fahey, figured out she could end the gerrymandering which had let the Republicans dominate her state by putting a ballot initiative before the voters. She needed 315,000 signatures. In one of the few good news stories about social media, she was able to use Facebook to gather 410,000 signatures in 110 days without any paid staff. In 2018, the reform won with an amazing 61% of the vote. Another initiative that dramatically expanded voter access through automatic and election-day access passed by 66%.

The end of gerrymandering enabled Democrats to flip both houses in Michigan in 2022, “giving them control of state politics for the first time in 40 years”. And in Wisconsin, the election of an additional liberal justice to the state supreme court finally ended Republicans’ domination of the state government.

The hopeful message is clear: despite massive Republican efforts to suppress liberal votes, it is still possible for a well-organized grassroots campaign to overcome the millions of dollars spent every year to prevent the triumph of true democracy.

• Minority Rule is published in the US by Farrar, Straus and Giroux