(CNN) -- The midterm elections dealt a powerful blow to President Obama and the Democratic Party as the country appeared to shift decisively to the right, moved by mass anger, "due to a combination of two kinds of fear," historian Michael Kazin told CNN.
Anger, he said, "that the economy will not recover soon and that the federal government is usurping power that should be wielded by private citizens, in and out of business."
To no one's surprise, Republicans seized control of the House of Representatives and sharply eroded Democratic advantage in the Senate.
But the wave of 2010 did not necessarily deliver an unambiguous mandate for the Republicans. That's because of the complicating, confounding factor of the Tea Party, the motley collection of grass-roots organizations that garnered attention and influence at levels far beyond their numbers. "They managed to capture the imagination of the media in a way conservative activists have not done since the birth of the new Christian Right over three decades ago, " Kazin said.
The Tea Party's wrath was hardly directed solely at Democrats, and while Kazin said the GOP would love to co-opt and control the Tea Party faithful, history suggests that this will be hard to do. Insurgencies don't like being told to behave themselves.
Kazin, a professor of history at Georgetown University, editor of The Princeton Encyclopedia of American Political History and author of "A Godly Hero: The Life of William Jennings Bryan" and other books, spoke to CNN last week.
CNN: Would Republicans have captured the House without the Tea Party?
Michael Kazin: We historians hate counterfactual questions! But clearly, the aura of a grass-roots rebellion helped to obscure the fact that most of corporate America was rooting for the GOP and helping finance Republican campaigns. The specific policy ideas of the Tea Partiers mattered less than did their anger at the perceived sins of "big government" and of President Obama. As [political writer] Kevin Phillips once wrote, much of political conflict comes down to the question of "who hates whom."
CNN: How well did the Tea Party do in this election?
Kazin: It's not clear from the exit polls how many people voted for a candidate largely because they were endorsed by Tea Partiers. The Tea Party is not a single organization, but a welter of them, some of which are tiny and without much funding, others of which are large and funded by national organizations like FreedomWorks.
An endorsement, by itself, was probably not enough to get a candidate elected in a swing district. A winning candidate had to be attractive in his or her own right. For example, Christine O'Donnell in Delaware was a disaster, but Ron Johnson in Wisconsin was a big hit. Both were endorsed by Tea Partiers in their states.
CNN: Based on the arc of the Tea Party's development and the outcome of the election, how is it different from past populist eruptions?
Kazin: The Tea Partiers are ideologically similar to every mass conservative upsurge from the early 1950s to the present: They favor an essentially unregulated economy, no large government presence with the exception of the military and the national security apparatus, and the moral values taught in evangelical Protestant and traditional Catholic churches.
But they have motivated more people against a perceived "socialist takeover" of the government than other conservative populist movements ever did. And they managed to capture the imagination of the media in a way conservative activists have not done since the birth of the new Christian Right over three decades ago.
CNN: How long will the kind of mass anger that the Tea Party is channeling last? And how can Obama tap some of the anger and benefit from it?
Kazin: The mass anger is due to a combination of two kinds of fear: that the economy will not recover soon and that the federal government is usurping power that should be wielded by private citizens, in and out of business. To a certain extent, the new GOP-controlled House can mollify the latter fear, but it will take a vigorous recovery to address the fears of long-term joblessness.
The core of the Tea Party is composed of committed conservatives who will never support Obama, no matter what he does. So he will have to address the fears and anger among independent voters that helped the movement gain some traction among people who aren't ideologues; he can't win over his sworn enemies.
CNN: What strands of the argument will endure? Tax cuts? Spending cuts? No to health care reform? And how will that affect Obama in the second half of his presidency?
Kazin: Again, the answer depends on what happens over the next two years or, if Obama wins re-election, the next six. Most Americans are, as two political scientists wrote back in 1967, "ideological conservatives but operational liberals." They want the government to help them in a variety of ways, but they rail at "big government" and think their taxes are too high.
Obama will have to make a vigorous argument about the need to continue the programs passed in the 111th Congress in order to restore prosperity and to improve the health care system.
He may not win over as many independents as he would like, but if he caves into his conservative opponents, he will appear weak and indecisive and open the way for a primary opponent on his left.
CNN: Could the free-form anger and frustration that motivated the Tea Party faithful this time crystallize into something enduring, or does it fragment and dissolve?
Kazin: The Tea Partiers are essentially a loosely organized faction of the Republican Party. It is very doubtful that they will break away from the party to have a separate and durable existence. I suspect they will continue to exist as a movement up to the 2012 election and dissolve rather quickly after that -- whether the Republicans retake the White House or not.
CNN: Will Tea Party purism be co-opted by Republican powers that be in the new Congress?
Kazin: Republican leaders will certainly try to co-opt the Tea Party's ideas; in fact, they did so during the 2010 campaign to a large extent. And in their post-election statements, John Boehner and Mitch McConnell promised not to compromise with the Democrats on any important issue, and McConnell's stated objective is to defeat Obama in 2012.
They clearly intend to give Tea Partiers little reason to doubt their resolve. Whether they can hold that stance in the give-and-take of legislative maneuvering is a different question.
CNN: How do you think Obama -- and the Democrats -- will make the case for themselves in 2012?
Kazin: That's an open question at this point. They have two quite different options: to continue to talk of cooperation with the GOP and of reducing the deficit and perhaps scaling back health care reform or to stand by the essentials of what they accomplished in the last Congress and to take steps, such as doing away with "don't ask, don't tell" and calling for comprehensive immigration reform that will delight parts of the Democratic base but will force confrontations with most Republicans.
CNN: How will the winning Tea Party candidates work in the new Congress if the mood shifts away from generalized rage toward that compromise and a willingness to make difficult governing decisions?
Kazin: It will be a test of whether they can govern as well as they campaigned. With a divided government, hard-core conservatives will not get all or even most of what they want. But if, like liberals during the Reagan years and G.W. Bush's administration, they pursue a patient, long-term strategy, their influence can continue to grow.