Political earthquake in Virginia

Experts caution against reading too much into a single vote — in a primary ballot in the United States mid-term elections, no less — but the defeat of Eric Cantor, the second-ranking Republican in the House of Representatives by the unheralded David Brat is a stunner.

Cantor’s loss is a sobering moment for all U.S. politicians and has upended the conventional wisdom about the tea party’s slide into oblivion. As a result, Republican candidates will tack right against such challengers. Expect yet more gridlock in Washington for the next two years.

Cantor, a seven-term incumbent, was number two in the Republican Party hierarchy in the House of Representatives and was considered by many to be the real leader of a conservative movement within the GOP. He styled himself as one of his party’s “Young Guns,” sporting brash new ideas and actively courting tea party voters.

His pugnacious style and his determination to reject business as usual in Washington earned him the enmity of President Barack Obama and Democrats within the Congress. It also appealed to voters: In the 2012 GOP primary just two years ago, Cantor crushed his opponent with nearly 80 percent of the vote.

This time, however, Cantor seemed to take re-election as a given and, while outspending his opponent 35 to 1, failed to take Brat, a professor of economics at Randolph-Macon College in Ashland, Virginia, seriously. Perhaps Cantor believed that his constituents would not turn their backs on the seniority he enjoyed and the benefits it brought to his district. Or maybe his attitude reflected internal polls that showed Cantor up by 35 points before the election.

Apparently the hard core of conservative voters who turned up for last week’s primary were not impressed. While more than three-quarters of a million people live in Cantor’s district, just 65,000 of them cast ballots in the primary.

Among those that showed up on June 10, Cantor was not so much a leading figure in the party as another Washington politician who put his own needs, and that of the “system” of which he was an integral part, above their own.

When the dust cleared, Brat had won 55.5 percent of the vote and Cantor became the first House majority leader in history to lose a primary renomination.

For many Republicans, the lesson to be learned from Cantor’s defeat is that you cannot be too conservative in primary elections. Immigration, in particular, is not to be touched: Brat attacked Cantor for an apparent willingness to compromise on that topic — a criticism that is especially ironic since the White House sees Cantor as an implacable foe of its attempts to change immigration policy. If that hard line prevails within the GOP, then immigration reform will never make it to the floor of Congress and, given the demographic changes underway in the U.S., the Republican Party will face minority status in national elections for a generation to come.

The larger lesson for many Republicans will be that compromise when dealing with political opponents is a mistake. Instead, ideological purity is to be prized above all else, and defeat is preferred to the surrender of principle. This is the basic position of the tea party movement, which many observers thought had reached its high-water mark.

Since the defeat of Mitt Romney in the 2012 presidential election and the failure of the Republican Party to retake the Senate, there has been a battle within the GOP for the soul of the party, with “establishment” Republicans battling tea party insurgents for supremacy.

The prevailing narrative is that the old guard was ascendant; the victory of Mitch McConnell of Kentucky on May 20 against a tea party challenger was proof of the mainstream’s return. The reality is more complex, however: The entire GOP has moved to the right, so that all primary candidates are largely indistinguishable.

The immediate question for the GOP is how competitive Brat will be in the general election when he meets Jack Trammell, another Randolph-Macon College professor. He was a last-minute choice by the Democratic Party, which did not expect Cantor to lose the primary.

The prospect of a tea party resurgence has Democratic Party strategists rejoicing as they anticipate a shift to the right by the GOP in the midterm elections later this year and the 2016 presidential campaign.

Still, most observers believe that the GOP will maintain its majority in the House and will retake control of the Senate in the November vote. The electoral math works against the Democratic Party: Too many of their seats are up for election in states that voted for Romney in 2012. A GOP-controlled Congress that is hostile to the very concept of compromise promises yet more gridlock in Washington.

Tough issues such as immigration will be sidelined and high-profile political initiatives, such as hearings about the behavior of the Internal Revenue Service or the Benghazi tragedy — the assaults on Sept. 11, 2012, by Islamic militants that left four Americans dead — will get attention.

There is a real danger that extreme positions on honoring U.S. debt could prevail, forcing a political and constitutional showdown between Obama and Congress.

As bad as U.S. politics seem right now, they could get even worse if a permanent campaign becomes the norm until the 2016 election.