In a fiercely worded speech, Senate Minority Leader Mitch McConnell, R-Ky., accused President Obama of violating citizen's First Amendment rights and denounced legislation that would require Super PACs to disclose the names of contributors.The conservative think tank American Enterprise Institute hosted McConnell on Friday, where he addressed First Amendment rights in light of the Supreme Court’s much argued Citizens United case. The decision rejects spending limits in federal elections for companies and unions.McConnell has been supportive of the controversial 5-to-4 ruling and hasurged the justices to reaffirm the decision in the face of a pending legal challenge.Democrats have pushed the Disclose Act in response to the ruling that would mandate third party groups reveal who donated to pay for election ads, but the measure has failed to move forward in Congress.McConnell says the measure amounts to harassment and an attempt to intimidate conservative donors and organizations."What this bill calls for is government-compelled disclosure of contributions to all grassroots groups, which is far more dangerous than its proponents are willing to admit," he says. "Because if disclosure is forced upon some but not all, it’s not an act of good government, it’s a political weapon…This is nothing less than an effort by the government itself to exposes its critics to harassment and intimidation."Earlier this week, President Obama’s senior campaign adviser David Axelrod said super PACs are hurting democracy and promise finance reform would be a top issue in a second-term."People are writing $10 million checks in one fell swoop to these super PACs—in many cases, they're undisclosed," Axelrod has said. Ninety-eight percent of our contributions are under $250. The average contribution is around $51. It would take 181,000 of our contributions to match one of those anonymous contributions. That's just a concern not just for us but for our democracy."Supporters of financial disclosures include U.S. Rep. John Yarmuth, D-Ky., who was an original co-sponsor of the legislation. Those in favor of the Disclose Act argue it is necessary to hold outside groups accountable for their advertisements.During the speech, McConnell accused the Obama administration of "Nixonian" intimidation that rivals the Watergate-era.McConnell told AEI members the president is standing against free speech by encouraging attacks on conservative donors, such as the billionaire Koch brothers."President Obama has publicly accused the Koch’s of being part of a, quote, ‘corporate takeover of our Democracy,’ whatever that means. And not only did his campaign publish a list of eight private citizens it regards as enemies—an actual old-school enemies list—it recently doubled down on the effort when some began to call these thuggish tactics into question," he says.The GOP leader also alleged that Tea Party groups have been targeted by government agencies, such as the Internal Revenue Service requesting to see attendance lists, meeting transcripts and donor information.The IRS has denied accusations that it selects groups for scrutiny based on their political views.Read McConnell's speech here.