Jeremy Corbyn is announced as the leader of the Labour Party in London. Some of the same forces that were instrumental in bringing Corbyn to power have powered Bernie Sanders’s rise in the U.S. (Kirsty Wigglesworth/AP)

The election of Jeremy Corbyn, the left-wing back-bencher, as the new leader of the British Labour Party raises the inevitable question: Can it happen here? Can Bernie Sanders, the independent socialist senator from Vermont, capture the heart and soul of the Democratic Party?

The immediate answer: He remains an underdog candidate for the Democratic nomination. But some of the same forces that were instrumental in bringing Corbyn to power have powered Sanders’s rise from a hopeless cause to a candidate who now leads Hillary Rodham Clinton in New Hampshire and in at least one poll in Iowa, and who has closed the gap with her nationally.

In a time of economic insecurity and an anti-establishment mood among so many voters here and elsewhere, the unexpected is no longer unthinkable. If Clinton’s problems and Sanders’s success are part of a surprising summer of politics here, the Corbyn victory was even more unthinkable only a few months ago after Labour suffered a historic defeat in the general election.

Here and in Britain, a political evolution continues. The election of Corbyn represents a dramatic break with the recent history of the Labour Party, a full and conspicuous rejection of the New Labour philosophy of Tony Blair, the former prime minister who won three successive elections but who now is a reviled figure for his role in prosecuting the war in Iraq in partnership with former president George W. Bush.

To American audiences, it is difficult to overstate the degree to which Blair is now an outcast in British politics. He may retain some affection here in the United States, but not in Britain. If there were any doubts about his current place in the politics of his country and particularly in the party he restored to prominence in the 1990s, it became clear with Corbyn’s landslide victory.

Sen. Bernie Sanders (I-Vt.), a White House contender in 2016, is known for his stances on budget issues and war. Here are his takes on Obamacare, Social Security and more. (Julie Percha/The Washington Post)

The Labour Party has been in turmoil since the general election in May, when Prime Minister David Cameron’s Conservative Party scored a surprising victory, securing an outright, if narrow, parliamentary majority when almost all polls predicted another hung Parliament and the possibility of a back-door path to power for Labour under its then-leader, Ed Miliband.

The election proved a wipeout for the Labour Party. Miliband resigned immediately, and as the party began the search for a new leader, it was plunged into a tumultuous debate about its future direction — a debate that hardly will be settled with the Corbyn election.

Blair weighed in days after the general election, warning that Labour had veered too far left under Miliband and that the road back to power required the party to recapture the center ground it had held from 1997 until 2010. As polls showed Corbyn rising, Blair warned of the potentially fateful consequences of an even sharper left turn.

Corbyn advocates a return to the kind of policies — nationalization of some industries, withdrawal from NATO — that had decimated the party decades earlier and brought Margaret Thatcher to power. But Labour Party members were in no mood to listen to Blair or to others in the party establishment. Corbyn won a first-ballot victory with almost 60 percent of the vote. The candidate who most closely reflected Blair’s centrist views finished with just under 5 percent of the vote.

Blair was not operating in a vacuum as he sought to modernize his party during the Thatcher era in Britain. Bill Clinton was doing the same thing in the United States in an effort to restore the Democrats to power during the Reagan era. Clinton created the template that Blair adopted: New Democrat and New Labour. His election in 1992 and reelection in 1996 foreshadowed Blair’s and Labour’s in 1997.

Both acknowledged the vulnerabilities of their own parties, adapted to the more conservative views of the electorates of the time — on crime and welfare, for example — and put a relentless focus on middle-class economics. For a decade or more, Clinton and Blair stood together as symbols of a new, centrist approach to politics.

Hillary Clinton was a full partner in those endeavors, developing a close relationship with Blair and the New Labour intellectuals and strategists as they sought to remake center-left politics in their countries and elsewhere.

The direct parallels between what has just happened in Britain and what is happening here in the United States are limited. Labour was driven from power five years ago and suffered an even more humiliating defeat in May. President Obama’s two election victories have kept Democrats in power in the White House.

Although Democrats have suffered humiliating defeats in two midterm elections in that time, they have not been faced with the kind of back-to-basic question about their philosophy and policies that Miliband’s defeat and resignation triggered there. And yet, Clinton has found herself struggling with many of the same forces on the left that just swept aside the Labour Party establishment.

Sanders, like Corbyn, has tapped into the economic unrest that remains in the wake of the 2008 financial crisis, manifested in debate about income and wealth inequality and fed by resentment that the bankers whose actions helped trigger the collapse have paid no significant penalty, which average families have.

Clinton has tried to adapt. She is not clinging to New Democrat rhetoric, nor articulating, as Blair did, a defense of center-ground politics. Her rhetoric has tried to echo the times. Her policies have shifted less, certainly less than those Sanders advocates.

The public mood also has put a greater premium on authenticity, rather than skilled and practiced policies. Sanders is old school, rumpled and unpolished, out of the same mold as Corbyn, characteristics that are appealing to many people sick of packaged politicians. Clinton has yet to find this voice.

Corbyn’s critics were describing his victory Saturday as a catastrophe for the Labour Party, a development that could relegate one of the two major parties to the fringes. No one around Clinton has yet made that argument against Sanders. Where she differs with Sanders, Clinton has been reluctant to make an all-out fight. She has tried to maneuver carefully between a Blairite past and an accommodation with a more progressive future.

Clinton still has many advantages. The process of winning a presidential nomination here is far different than becoming leader of the Labour Party. Money and machinery count heavily, and victory must come repeatedly through the course of primaries and caucuses in all the states. But the Democrats are inching toward a more rigorous debate, and the British example could serve as a catalyst for engagement.