The US Supreme Court has struck down Roe vs Wade, the legal decision that has enshrined the constitutional right to an abortion for nearly 50 years, in a dramatic ruling by the court’s conservative majority that will shake up American society, politics and jurisprudence for years to come.

In the decision authored by Justice Samuel Alito, the justices of the Supreme Court upheld a state law in Mississippi that bans abortion after 15 weeks. They also went further, saying that the Roe vs Wade ruling of 1973 was incorrectly decided. The court’s three liberal justices dissented.

The court’s ruling was one of its most intensely anticipated in years — even more so after a draft of the majority opinion heralding its final decision to overturn Roe vs Wade was published by Politico in April, triggering a highly unusual probe within the institution into the leak. 

In denying a constitutional right to an abortion, the court has effectively given a green light for states to enact abortion laws that can be as restrictive as they wish. Several states run by Republican-led governors and legislatures have already passed laws that mean more restrictions on abortion will be automatically implemented if Roe is overturned.

The sweeping opinion in the Mississippi case was made possible by the appointment of three conservative Supreme Court justices during the presidency of Donald Trump, who secured their confirmation through the then Republican-led Senate. The court’s conservative majority is now so strong that it can afford to lose the support of Chief Justice John Roberts, who is considered a more moderate conservative, and still prevail in key rulings.

Earlier this year, the Democratic-led Senate confirmed Ketanji Brown Jackson, a liberal nominated by Joe Biden, to be a justice on America’s highest court. Since she is replacing Stephen Breyer, another liberal, her appointment will not affect the court’s balance of power.

The Supreme Court ruling on abortion was released with less than five months to go before November’s midterm elections, and may alter the political dynamic heading into the vote, though it is unclear whether it can overpower the impact of high inflation and economic perceptions as a factor for voters.

With polls showing that a majority of Americans opposed to overturning Roe vs Wade, Democrats are hoping that the ruling will trigger outrage, mobilise its base, and attract moderate swing voters who will see Republican positions on the issue as increasingly extreme.

But Republicans believe that disappointment with Biden’s handling of the economy, and high consumer prices, particularly for food and petrol, will still carry the day and give them a strong chance of recapturing control of the House of Representatives and possibly even the Senate.