The facts in the European debate are hotly disputed, but some estimates suggest that three-quarters of all laws affecting the United Kingdom originate from within the European Union, as this deeply political enterprise is now called. 40 percent is probably a more accurate estimate. Whatever the true number, it is still a huge proportion and a proportion that the British people never envisaged when they were asked for their consent in 1975.

Thatcher made her political mission clear in a landmark speech in 1988, delivered in the Belgian city of Bruges. “We have not,” she thundered, “successfully rolled back the frontiers of the state in Britain, only to see them reimposed at a European level.” She did not just object to Europe taking a socialist turn. She hated the very idea of what she called “a European superstate exercising a new dominance from Brussels.” The leader who had fought the unions and the Soviet Union during her early years in power had new enemies in her sights: the big state and a big, antidemocratic European project.

When Europhiles ousted her in November 1990, exploiting unpopularity caused by an economic recession and a controversial tax reform, they hoped to end her attempts to lead the Conservative Party in a Euroskeptic direction. But the successful “regicide” against Thatcher was far from the end of the matter. It was only the beginning. For all of the last twenty-five years, a battle has raged inside the Conservative Party as to what kind of relationship Britain should have with the rest of Europe. In opposing further European integration or even supporting exit from the EU, many Conservatives believe that they are following the orders that Thatcher issued in 1988. Many other skeptics decided, however, that the establishment factions within the Conservative Party that toppled Margaret Thatcher would never allow the Tories to lead Britain out of Europe. Many of those skeptics joined UKIP and to this day believe that the Conservative Party can never be trusted to ensure that Britain becomes an independent, self-governing nation again.

ALTHOUGH EUROPE may be the issue that motivated its earliest supporters, it does not directly explain why UKIP finished first in this May’s European Parliament elections. The secret of UKIP’s growing success is that Nigel Farage has broadened his party’s message. It no longer talks just about Europe. At the end of a TV debate with Nick Clegg, Farage invited viewers to “come and join the people’s army.” He continued: “Let’s topple the establishment who led us to this mess.” By “this mess” he means the global recession, foreign interventions, political corruption and, most of all, large-scale immigration.

The British electorate never endorsed large-scale immigration at any general election, but during Tony Blair’s time at 10 Downing Street a net three million people—equivalent to 5 percent of the population—entered Britain. And despite the current Conservative-led government’s promises to bring numbers under control, net immigration into Britain is still proceeding at a historically unprecedented level of two hundred thousand people per year. Immigration experts predict seventy million people will be living and building upon Britain’s green and pleasant lands by 2030.

Many argue that immigration has brought significant benefits to Britain. London is enjoying its second great age, for example, because of the energetic and highly skilled people from many parts of the world who are working in its creative sector and its financial and information-technology industries. Many of the great brains working in Britain’s universities and teaching hospitals are also immigrants. But there have been significant downsides to immigration as well. Housing prices are rising to record levels, especially in the southeastern parts of England—making ownership unaffordable for many local and young people. Immigration may also partly explain the depressed nature of the wages of lower-skilled people. British employers have little incentive to cooperate with the government’s welfare-to-work programs so long as foreign workers, motivated to cross continents in search for work and therefore certainly motivated to turn up for work at 5 a.m., are ready and available to take the jobs they create.

But whatever the arguments for and against immigration there is one stubborn fact that immigration advocates cannot escape: the British people have never voted for large-scale immigration of the kind that has occurred. Any political party that promised immigration of two or three hundred thousand people per year would not do well at elections. Three-quarters of British voters want net immigration reduced to lower levels. Immigration control was what the Conservative Party vowed to deliver before the last election. While David Cameron and his home secretary, Theresa May, have succeeded in reducing immigration, they have not come close to meeting their promised target. This failure is the number-one policy factor driving UKIP’s progress.

Immigration is in fact the perfect issue for UKIP. First, there is the policy substance: voters disapprove of large numbers of people entering Britain, pushing up housing prices and “stealing our jobs.” Second, there is the antiestablishment dimension: all of the three major political parties have promised to control immigration but once in power were proven to have “lied,” claims Farage. And third, there is the European dimension. So long as Britain is a member of the EU, it does not have control of its borders. Free movement of labor is an integral component of the European single market—negotiated, ironically, by Thatcher herself. Just as any Briton is free to live and work in any other part of the EU, so any Bulgarian, Romanian or Pole is free to come to live and work in the United Kingdom. Any potential limits on immigration into Britain from outside of the EU can be overwhelmed by immigration from inside the EU—especially from its poorer, recession-struck member states. As the only party promising to take Britain out of the EU, UKIP is therefore the only party with a credible policy to control immigration.

OVER TIME, UKIP has devoted more and more of its campaigning efforts to opposing immigration. Sometimes, however, this has led UKIP to appear as anti-immigrant as much as anti-immigration. Although a majority of ethnic-minority Britons as well as white Britons oppose large-scale immigration, UKIP’s sometimes strident emphasis on the issue helps to explain why it is such a white party. 14 percent of Britons come from ethnic minorities, yet a recent collage of hundreds of UKIP members, produced by the party itself, contained not one nonwhite face.

UKIP also opposes gay marriage, wants the foreign-aid budget slashed and takes an even tougher line on welfare payments to the poor than the governing Conservatives. The overall impression that has been created is that UKIP supporters don’t much like modern Britain or people that they do not know. It is in danger of becoming a very traditionalist, even reactionary party. That was not its original intention. UKIP still describes itself as a libertarian party, and in supporting smokers’ rights and opposing state surveillance, for example, it retains some freedom-loving beliefs.

If UKIP is to become a permanent force in British politics, it will need to decide how to resolve this conflict between its libertarian and traditionalist tendencies. If it moves in a libertarian direction, it might alienate the older, more conservative voters that form its current bedrock of support. If it does not become a little more open-minded and reach some of Britain’s “educated, cultured and young” voters, it will struggle to make the parliamentary breakthroughs necessary to really change British politics and secure its founding goal: exit from the European Union.

WHATEVER FUTURE UKIP might carve out for itself, it has already posed huge questions for the mainstream parties. For twenty or more years, much of British politics has become far removed from the concerns of large numbers of voters. Often using campaigning techniques imported from America, the established parties have become adept at targeting swing voters in swing parliamentary seats. As a result, only a few million, largely middle-income voters decide Britain’s government. Half of British parliamentary seats haven’t changed hands since 1970. Nearly one-third have remained in the same party’s control since 1945. Without America’s system of primary elections, most British MPs think they have a seat for life. This has led many of them to become indifferent to their constituents’ concerns. It is a recipe for political stultification. It is certainly a breeding ground for disenfranchisement. The people who need politics most—the people struggling to make ends meet, who run out of money at the start rather than the end of months—are most shut out from the electoral system. UKIP has given them a voice.

Establishment politicians on both sides of the Atlantic can choose to see Britain’s UKIP—or America’s Tea Party, for that matter—as irritants. They can paint them as extremists. They can attempt to defeat them. And it is certainly true that both movements have weaknesses. But the establishments also have their weaknesses. Too many influential Republican politicians grew too close to special interests on Wall Street and to the big-business lobbyists of Washington’s K Street. They came to embody a crony rather than a competitive form of capitalism—let alone a Main Street capitalism rooted in local communities. The result was the Mitt Romney candidacy and the devastating finding that among those who said that whether a candidate “cares about people like me” was a top concern for them, a full 81 percent voted for Barack Obama rather than the Republican nominee.