As the Tea Party celebrates its five-year anniversary, many commentators are asking whether the grassroots anti–Big Government movement is still relevant.

In some ways, this seems a silly question. The Tea Party has been enormously successful in changing the terms of the national debate on issues such as debt and spending. And, while its favored candidates have suffered some high-profile defeats, it has also won important victories. The Republican midterm sweep of 2010 would not have been possible without its energy and enthusiasm.

Yet it’s also true that the Tea Party’s clout is waning. According to the most recent Gallup poll, just 30 percent of Americans have a favorable opinion of the movement, the lowest level in its history. This seems particularly unsettling when polls also show that the public still overwhelmingly supports the Tea Party objective of limited government. In fact, a recent Gallup poll shows a record 72 percent of Americans feels that big government is the greatest threat to the future of the country. Voters who feel that way should be flocking to the Tea Party in droves.

They are not.

Some of it might be a question of tactics. Americans tend to dislike confrontation from their political leaders. Certainly, things like the government shutdown tended to turn off some voters, especially when misrepresented by a biased media. The overheated rhetoric of some tea-party leaders may also drive away otherwise sympathetic voters. Calling every dissenting Republican a RINO or inferring that President Obama is some sort of crypto-Muslim Communist is not going to win friends or influence people. Some tea-party activists definitely come across as a bit over-caffeinated.

But there is also a more fundamental issue at play here: Is the Tea Party still the Tea Party?

Sparked by outrage over the Wall Street bailouts, the original Tea Party was motivated by an opposition to Big Government. The motto of the Tea Party Patriots, one of the largest and most influential groups, was “fiscal responsibility, limited government, and free markets.” The Tea Party’s core issues were the skyrocketing national debt and opposition to Obamacare.

Social issues were not part of the platform. In fact, Jenny Beth Martin, leader of the Tea Party Patriots told the New York Times, “When people ask about [social issues], we say, ‘Go get involved in other organizations that already deal with social issues very well.’ We have to be diligent and stay on message.”

In an April 2010 CBS News/​New York Times poll, barely 14 percent of Tea Party supporters said social issues were more important to them than economic issues.

As a result, the group was able to build a broad coalition of economic conservatives — traditional Republicans, of course, but also libertarians, and fiscally conservative socially tolerant suburbanites who had drifted away from the GOP in recent years. In national surveys, roughly 40 percent of Tea Party supporters once described themselves as libertarian or libertarian-leaning.