A new survey challenges the conventional wisdom that the Tea Party movement in the US is a secular libertarian movement and in fact demonstrates the religious zeal in its ranks. The results of the polling, by the Washington DC firm Public Religion Research Institute (PRRI), show that nearly half of respondents who consider themselves part of the Tea Party movement are also part of the religious right, and of the 81% of Tea Partiers who identify as Christian, 57% consider themselves part of the religious right. Only 15% of Tea Partiers, according to the PRRI poll, don't have a religious affiliation.

These results confirm what I have found reporting on the intersection of the Tea Party and religious right: that the Tea Party movement is driven in no small measure by religious fervour, and that religious-right political elites have deliberately injected themselves into the movement, both as a matter of common cause and political expediency.

The conventional wisdom that the Tea Party movement is a secular one is rooted in its portrayal as a spontaneous uprising of disgruntled, ordinary citizens against "big government" and alleged "socialism". Indeed, the Tea Partiers who find their inspiration in CNBC reporter Rick Santelli's rant against government help for people facing foreclosure may indeed have a secular motivation. Still others look to Republican congressman Ron Paul, the 2008 presidential hopeful, as the libertarian brainchild of the Tea Party zeitgeist. But anyone who sees Paul as a secularist fails to grasp the theocratic roots of his politics, and of many Tea Party activists.

Although Paul ran as a Republican, he later endorsed the nominee of the Constitution party, Chuck Baldwin, a pastor and activist who convened a "black-robed regiment" of rebellious pastors before Glenn Beck did. The Constitution party's platform declares, among other matters of Christian governance: "The goal of the Constitution party is to restore American jurisprudence to its biblical foundations and to limit the federal government to its constitutional boundaries." Sharron Angle, the Nevada senate candidate and Tea Party favourite, once belonged to the Constitution party's state affiliate. The Constitution party was founded by conservative icon and Christian reconstructionist Howard Phillips. Christian reconstructionists – who have informed the religious right, its political leadership, the home-schooling movement, and now the Tea Party – believe that the federal government has exceeded its God-ordained authority. They believe that it is in fact "tyrannical". And some believe it needs to be challenged, or even overthrown.

The PRRI survey found that the Tea Party movement is dominated by social conservatives: 63% said that abortion should be illegal in all or most cases, and only 18% supported gay marriage. This should provide an obvious enough refutation to the purveyors of the theory that the Tea Party movement is disinterested in "social issues". But looking at Tea Partiers' concerns about sex and sexuality just scratches the surface of the Tea Party/religious right alliance. The shared view on government is far more instructive.

To be sure, Christian reconstructionists (and those influenced by it, even if they don't realise or admit to it) are adamantly opposed to abortion and same-sex marriage, and indeed to rights for women and LGBT people. But to understand why the Tea Party resonates with the religious right and vice versa, one must understand how the anti-government rhetoric of the Tea Party movement is driven by a fundamental tenet of Christian reconstructionism: that there are certain God-ordained spheres – family, church and government – and that government has exceeded the authority God gave it, to the detriment of church, family and the individual, whose rights, both Tea Partiers and religious right-ists maintain, are granted by God, not the government.

This notion that the federal government – not only godless, but in flagrant violation of God's will – is "tyrannical" and needs to be overthrown resonates from militias to the John Birch Society to the podiums of religious-right gatherings where Republican presidential hopefuls jockey for the support of the faithful. To fail to see the religious roots of the Tea Party mantra – or the ways in which it reverberates as a divine imperative – is to blind oneself to a fundamental feature of American conservatism.