Political gridlock empowers US justices Antonin Scalia, the US Supreme Court's most colourful conservative, issued a furious dissent from the bench on its ruling advancing gay rights this week, saying that his fellow justices had "an exalted notion" of their role in American democracy. The ruling, in which a 5-4 majority struck down a federal ban on same-sex marriage, was "a judicial distortion" of debate over the issue, he said, "a debate that can seem in need of our clumsy "help" only to a member of this institution." But Justice Scalia's dissent, read aloud to his captive colleagues sitting beside him, may have obscured a larger point about the court - that political gridlock in Congress is making the institution more powerful than ever. The Supreme Court displayed in full its role as the third branch of government under the constitution, by striking down a totemic civil rights law on Tuesday, and then, the next day, Bill Clinton's same-sex marriage ban. The court has often been forced to the frontline of politics in the US, propelling an end to school segregation in 1954 and effectively deciding the deadlocked 2000 election between George W Bush and Al Gore. But the activism of the conservative-leaning court under Chief Justice John Roberts stands in contrast to today's Congress, just across the road on Capitol Hill. The Democrats, who control the White House and have a majority in the Senate, and the Republicans, in command of the House of Representatives, have lurched from crisis to crisis, largely over the budget, since 2010. One of the few exceptions to the deep partisan divide is on the national security state, with both parties largely rushing to back Barack Obama's defence of the reach of US intelligence at home and abroad after a series of recent leaks. The court's decision this week to declare void a key provision of the Voting Rights Act was especially striking, as Congress had voted overwhelmingly as recently as 2006 to reaffirm the 1965 law. The five judges in the majority in the case declared that "things had changed dramatically" since Congress passed the law mandating federal oversight of voting in states with a history of discrimination. The judges said voting tests had been abolished and the disparity in the turnout and registration of black voters had been erased. Because Congress has failed to update what the act covered, the judges did it for them. The court is almost acting as a "supra-legislature," said Kevin Outterson, a professor of law at Boston University. The judges may have sent the Voting Rights Act back to Congress for updating, he said. But in the current climate, what is the chance that Congress will be able to intervene? Virtually nil. Mr Outterson listed a number of cases where the court has decisively intervened, from pre-emption of state law for generic drugs to an expansion of healthcare for the poor, changes that Congress did not have the capacity to correct. The court's decisions are not predictable, largely because of the return of Justice Anthony Kennedy as the key swing vote on the nine-member bench. Mr Kennedy was the sole judge in the majority in both the key rulings on voting rights and gay marriage. "He is the only one who got what he wanted," said Akhil Reed Amar, a professor of law and political science at Yale University. Chief Justice Roberts, a George W Bush appointee, angered many conservatives when he ruled in favour of Mr Obama's healthcare law in the heat of the 2012 election campaign, although on different grounds than his liberal colleagues who formed the majority. But the court overall under Mr Roberts is one of the most conservative in recent memory, based on academic evaluations that assign ideological weight and value to each ruling. Studies by Lee Epstein, of the University of Southern California, tracking the court's decisions since the second world war rank the Roberts court as the most conservative in more than half a century. She does not think, however, that the court's ruling invalidating federal laws will necessarily stand. "It's probably harder for Congress to respond when it's divided, but that doesn't usually last forever," she said. Mr Amar believes that Congress will act on the decision on the Voting Rights Act, because it creates a "massive problem" for a divided Republican party struggling to attract black and minority voters. "As much running room as the court has, they went way too far and Congress will respond," he said. They have aligned themselves with the political extremists in the Republican party, and for [the Republicans], this is not a long-term winning strategy.