WASHINGTON – The Republican Party is ascendant, emboldened – and on the verge of debilitating mistakes.

There is little doubt about Republican ascendance. In June 2008, Democrats enjoyed a nearly 20-point lead in the generic congressional ballot; today they are behind. Approval for President Obama among independents has fallen below 40 percent for the first time in his presidency. Vice President Biden recently protested that he saw no “grand debacle” coming in November for Democrats, thereby giving a name to Democratic fears. A debacle seems precisely what’s in store.

But the problem with political waves is that they generate misleading momentum and exaggerated ideological confidence. Parties tend to interpret shapeless public discontent as the endorsement of their fondest ambitions. Obama mistook his election as a mandate for the pent-up liberalism of his party. Some Republican activists are intent on a similar but worse mistake.

The Republican wave carries along a group that strikes a faux revolutionary pose. “Our Founding Fathers,” says Nevada Republican Senate candidate Sharron Angle, “they put that Second Amendment in there for a good reason, and that was for the people to protect themselves against a tyrannical government. And in fact, Thomas Jefferson said it’s good for a country to have a revolution every 20 years. I hope that’s not where we’re going, but you know, if this Congress keeps going the way it is, people are really looking toward those Second Amendment remedies.”

Angle has managed to embrace the one Founding Father with a disturbing tolerance for the political violence of the French Revolution. “Rather than it should have failed,” enthused Jefferson, “I would have seen half the earth desolated.” Hardly a conservative model.

But mainstream conservatives have been strangely disoriented by tea party excess, unable to distinguish the injudicious from the outrageous. Some rose to Angle’s defense or attacked her critics. Just to be clear: A Republican Senate candidate has identified the United States Congress with tyranny and contemplated the recourse to political violence. This is disqualifying for public office. It lacks, of course, the seriousness of genuine sedition. It is the conservative equivalent of the Che Guevara T-shirt – a fashion, a gesture, a toying with ideas the wearer only dimly comprehends. The rhetoric of “Second Amendment remedies” is a light-weight Lexington, a cut-rate Concord. It is so far from the moral weightiness of the Founders that it mocks their memory.

The Republican wave also carries along a group of libertarians such as Kentucky Senate candidate Rand Paul. Since expressing a preference for property rights above civil rights protections – revisiting the segregated lunch counter – Paul has minimized his contact with the media. The source of this caution is instructive. The fear is not that Paul will make gaffes or mistakes, but rather that he will further reveal his own political views. In America, the ideology of libertarianism is itself a scandal. It involves not only a retreat from Obamaism but a retreat from the most basic social commitments to the weak, elderly and disadvantaged, along with a withdrawal from American global commitments. Libertarianism has a rigorous ideological coldness at its core. Voters are alienated when that core is exposed. And Paul is now neck and neck with his Democratic opponent in a race a Republican should easily win.

In addition, the Republican wave carries along a group more interested in stigmatizing immigrants than winning their support. Some conservatives have found Arizona’s anti-immigration law a cause worth fighting for – a law that is poorly written, ineffective, symbolically toxic and likely to be overturned.

The response of many responsible Republicans to these ideological trends is to stay quiet, make no sudden moves and hope they go away. But these are not merely excesses; they are arguments. Significant portions of the Republican coalition believe that it is a desirable strategy to talk of armed revolution, embrace libertarian purity and alienate Hispanic voters. With a major Republican victory in November, those who hold these views may well be elevated in profile and influence. And this could create durable, destructive perceptions of the Republican Party that take decades to change. A party that is intimidated and silent in the face of its extremes is eventually defined by them.

This is the challenge of a political wave. It requires leaders who will turn its energy into a responsible, governing agenda. So far – in Congress, among conservative leaders, among prospective presidential candidates – that leadership has been lacking.

And so the Republican Party rides a massive wave toward a rocky shore.

© 2010, Washington Post Writers Group