In honor of Constitution Day, Media Matters for America highlights Fox News' four-year campaign to declare the Obama administration unconstitutional.

During Obama's term in office, Fox News, the self-styled "voice of the opposition," has mindlessly accused Obama of violating the Constitution in response to a staggering number of policies with which the network disagrees.

Here are a few examples of Fox's campaign against the constitutionality of the Obama administration's actions:

• Fox News spent years declaring the Affordable Care Act unconstitutional. In June, the Supreme Court upheld the constitutionality of the health care reform law.

• When the Obama administration announced that it would prioritize deporting undocumented immigrants who pose a risk to public safety, Fox called it “administrative fiat” and “a pretty radical sort of in-your-face at the constitutional system.” The administration's use of prosecutorial discretion, however, is consistent with current law and has decades of precedent.

• Recently, when the administration announced that states could apply for welfare waivers, Fox called the move “clearly illegal” and an “executive fiat move.” But past presidents, including Ronald Reagan and George W. Bush, have used this waiver authority before.