The controversy over the IRS's harassment of conservative groups continues. President Obama's team continues to blame low-level bureaucrats. Some conservatives suspect a more sinister explanation: that the levers of government were used to attack an existential threat to the president's 2012 reelection. The president and his party dismiss this as a paranoid fantasy. The evidence, however, is enough to make one believe that targeting Tea Party groups would have been an effective campaign strategy going into the 2012 election cycle.

It is a well-known fact that the Tea Party movement dealt the president his famous "shellacking" in the 2010 mid-term election. Less well-known is the actual number of votes this new movement delivered-and the continuing effects these votes could have had in 2012 had the movement not been de-mobilized by the IRS.

In a new research paper, Andreas Madestam (from Stockholm University), Daniel Shoag and David Yanagizawa-Drott (both from the Harvard Kennedy School), and I set out to find out how much impact the Tea Party had on voter turnout in the 2010 election. We compared areas with high levels of Tea Party activity to otherwise similar areas with low levels of Tea Party activity, using data from the Census Bureau, the FEC, news reports, and a variety of other sources. We found that the effect was huge: the movement brought the Republican Party some 3-6 million additional votes in House races. That is an astonishing boost, given that all Republican House candidates combined received fewer than 45 million votes. It demonstrates conclusively how important the party's newly energized base was to its landslide victory in those elections, and how worried Democratic strategists must have been about the conservative movement's momentum.

The Tea Party movement's huge success was not the result of a few days of work by an elected official or two, but involved activists all over the country who spent the year and a half leading up to the midterm elections volunteering, organizing, donating, and rallying. Much of these grassroots activities were centered around 501(c)4s, which according to our research were an important component of the Tea Party movement and its rise.

The bottom line is that the Tea Party movement, when properly activated, can generate a huge number of votes-more votes in 2010, in fact, than the vote advantage Obama held over Romney in 2012. The data show that had the Tea Party groups continued to grow at the pace seen in 2009 and 2010, and had their effect on the 2012 vote been similar to that seen in 2010, they would have brought the Republican Party as many as 5 - 8.5 million votes compared to Obama's victory margin of 5 million.

President Obama's margin of victory in some of the key swing states was fairly small: a mere 75,000 votes separated the two contenders in Florida, for example. That is less than 25% of our estimate of what the Tea Party's impact in Florida was in 2010. Looking forward to 2012 in 2010 undermining the Tea Party's efforts there must have seemed quite appealing indeed.

Unfortunately for Republicans, the IRS slowed Tea Party growth before the 2012 election. In March 2010, the IRS decided to single Tea Party groups out for special treatment when applying for tax-exempt status by flagging organizations with names containing "Tea Party," "patriot," or "9/12." For the next two years, the IRS approved the applications of only four such groups, delaying all others while subjecting the applicants to highly intrusive, intimidating requests for information regarding their activities, membership, contacts, Facebook posts, and private thoughts.

As a consequence, the founders, members, and donors of new Tea Party groups found themselves incapable of exercising their constitutional rights, and the Tea Party's impact was muted in the 2012 election cycle. As Toby Marie Walker, who runs the Waco Tea Party, which filed for tax-exempt status in 2010 but didn't receive approval until two months ago, recounted recently: "Our donors dried up. It was intimidating and time-consuming." The Richmond Tea Party went through a similar ordeal, and was only granted tax-exempt status in December, right after the election--three years after its initial request. Its chairman explained the consequences: the episode cost the Richmond Tea Party $17,000 in legal fees and swallowed time the all-volunteer network would have devoted to voter turnout, outreach in black and Latino neighborhoods and other events to highlight the constitution and "the concept of liberty."

It might be purely accidental that the government targeted precisely this biggest threat to the president. It may just be that a bureaucracy dominated by liberals picked up on not-so-subtle dog whistles from its political leadership. Or, it might be that direct orders were given. In any case, it doesn't take a conspiracy theorist to note that the president's team was competent enough to recognize the threat from the Tea Party and take it seriously. The Obama campaign has made no secret of its efforts to revolutionize turnout models for the most recent campaign. Its remarkable competence turning out its own voters has been widely discussed, and it seems quite plausible that efforts to suppress the Republican vote would have been equally sophisticated.

We may never know to what exact extent the federal government diverted votes from Governor Romney and thus, how much it influenced the course of a presidential election in the world's oldest democracy. At the very least, however, Americans of all political persuasions can be forgiven for a little cynicism when the president has the nerve to say, as he did on May 5th in his commencement address to graduates of the Ohio State University: "You've grown up hearing voices that incessantly warn of government as nothing more than some separate, sinister entity that's at the root of all our problems. You should reject these voices." And that cynicism, that lack of trust in the country's governing institutions, becomes harmful quite easily: when the people are asked to have faith in the NSA's efforts to protect the nation from terrorist threats, for example.