The Stop Online Piracy Act (SOPA), authored by Rep. Lamar Smith (R-Texas) at the behest of Hollywood and the recording industry, inspired one of the largest and most organic opposition campaigns in recent memory. Twitter users put "STOP SOPA" banners on their user avatars; numerous sites, including Wikipedia, Google, and Reddit, "blacked out" in protest; and Congress eventually tabled the bill. Smith bore the brunt of the backlash. His biggest primary opponent, an Oath Keeper named Richard "Sheriff" Mack, has ridden the outrage like a wave.

Mack isn't opposed just to SOPA, but a slew of other acronyms that Smith has supported: TARP, NDAA, the PATRIOT Act. The former Graham County, Arizona sheriff announced he would run against Smith in the 21st District's GOP primary back in December, but his profile didn't blow up until this past Sunday, when the social media giant Reddit christened him the anti-Smith, and promoted his Ask Me Anything (AMA) question-and-answer session on the Reddit homepage. The Mack teaser sent a torrent of users to a thread titled "I am Sheriff Richard Mack. I'm challenging SOPA and PCIP Sponsor Lamar Smith (R-TX) to a Primary in a heavily conservative district."

By Reddit standards, the thread was a success. Many Reddit users seemed to agree that an ObamaCare opponent who also opposed SOPA was better than the ObamaCare opponent who wrote SOPA. After Mack laid out his opposition to the drug war, the PATRIOT Act, and the National Defense Authorization Act, one user wrote, "I hope you are not talking out of your ass, because I like you."

"No, I am sitting on it," Mack replied minutes later.

SOPA is just an entry point for Mack's campaign against federal overreach. "Lamar Smith has been a tax, borrow, and spend Republican, who has tried to increase the powers of D.C. with SOPA, TARP, and increasing the debt ceiling," Mack said. "His vote for NDAA gave more power to President Obama than all the Democrats put together."

Mack's own history is likely to raise a few eyebrows. He's spoken at John Birch Society events, encouraged local law enforcement officers to arrest IRS agents for trespassing, and been the subject of numerous reports about the rise of militias produced by the Southern Poverty Law Center. He believes in God, homeschooling, and the 10th Amendment. He's a survivalist. ("Sooner or later you'll wish you had some food storage on hand," reads Mack's endorsement for freeze-dried staples on his website. "No other food satisfies like animal protein during stressful times.")

Mack is quick to point out that he cares about tech businesses in the 21st District, such as the hosting giant Rackspace, whose facilities he recently toured. The experience, Mack wrote, "made me even more concerned about what's going with this type of censorship." Mack brought up Rackspace again when we spoke on the phone on Wednesday. "If SOPA went through as proposed by Lamar Smith, it could kill that business," Mack said. (Full disclosure: Reason, like a lot of companies, uses Rackspace.)

Freedom from Washington is the core of Mack's political philosophy. During his second term as sheriff of Graham County, Arizona, he was one of two plaintiffs in a suit against the Brady Handgun Violence Prevention Act that went all the way to the Supreme Court (Mack won).

After retiring as sheriff, Mack founded the Constitutional Sheriffs and Peace Officers Association (CSPOA), which enlists and trains sheriffs and peace officers (a term Mack prefers to "law enforcement officers") to "understand and enforce the constitutionally protected Rights of the people they serve, with an emphasis on State Sovereignty and local autonomy."

Until he declared his run for Congress, Mack's focus was on converting, or—if need be—running against local elected law enforcement officials. One of his goals for the 2010 campaign season, which he shared at a gathering of Oath Keepers in Three Forks, Montana, in July 2009, was getting CSPOA involved in 900 sheriff elections. "If any of you are spending your time and money on Washington, D.C., politics, you're wasting your time and money," he told the audience. "We're focused locally on the Constitution, and on the oath," he added. (Oath Keepers is a coalition of current and former law enforcement and military personnel who have pledged not to enforce laws that violate the Constitution.)

Now Mack's ready to take those ideas to Washington. "I also believe we should be promoting state sovereignty from the national level and that Lamar Smith should be in Washington protecting the 10th amendment," he said. "Follow the Constitution, or go home."

"I'll never tell the American people that if you just give us more money and more power next year, we'll make things better. I will never tell the American people that we can get a handle on the drug war. The drug war has been a failure and prohibition does not work. Smith will continue to fund that complete failure."

Mack also had choice words for the wars in Iraq, Afghanistan, and Libya, and the calls for a strike on Iran. "Smith has supported these wars; wars that were unconstitutional because there was never a declaration of war. We pretend that we have a national emergency with these wars, yet we refused to secure our own borders. The hypocrisy is astonishing."

Speaking of immigration, the former sheriff's stance is short on specifics, and boils down to border security: "I'm not talking about people coming from Guatemala and El Salvador," Mack said. "I'm talking about Middle Eastern terrorists [and] human trafficking." While he believes states should be able to "protect their residents from illegal immigrants," Mack opposed Arizona immigration law SB1070 because he said many aspects of it were unconstitutional.

Recently he launched a website called "A Buck to Crush SOPA," but has raised only $2,706 toward his $50,000 goal. That won't buy as much as Smith's 25-year war chest, though thanks to the Reddit promotion, "donations are coming in small, but very frequent." (On Thursday, Mack got still more tech attention, this time in a profile published on the popular tech CNET, written by Declan McCullagh.)

Smith, meanwhile, has been nearly untouchable for 25 years in the 21st District, which covers San Antonio and parts of Texas Hill Country. He's gone uncontested in nearly every one of his primaries, save for in 1992 and 2010 (he won with 81 percent of the vote in both years). His worst showing in a general election was in 2006, when he won with 60 percent of the vote. In 2010, he won reelection with 68 percent of the vote. According to campaign finance records, Smith has rasied nearly $660,000 for the 2011-2012 election cycle, and has collected more than $7 million over the course of his career.

There may be a bigger obstacle for Mack than money. Namely, the results you get when you Google him: reports from the Southern Poverty Law Center about his involvement with the John Birch Society and the militia movement, as well as his association with Ruby Ridge survivor Randy Weaver. (Weaver's son was killed and his wife was shot through the head by an FBI sniper during the siege on Weaver's farm, but the SPLC refers to him solely as a "white supremacist.")

"I've been worried about it for years," Mack said when asked if he thought the SPLC's reports would hurt him in his race against Smith. "The people who know me know that these are all lies and distortions. I'm a very peaceful person who loves America and loves Texas." In a December 2011 interview with the The New American, published by the John Birch Society, Mack told William F. Jasper, "I spent 20 years in law enforcement and never slugged or slapped or hit or maced or shot another human being. So I don't believe in violence and I'm not a violent person, nor have I been."

In the summer of 2011, the SPLC issued a correction for a claim it made about Mack: "Due to a transcription error, a story in the Winter 2010 issue of the Intelligence Report misquoted former Arizona Sheriff Richard Mack speaking at the Freedom Action National Conference last August. Mack did not say that he hoped that a sheriff would 'take out some IRS agents.' He said: 'My dear friends, I pray for the day that when the first sheriff of this country knows and understands his duty well enough, that he'll be the first one to fire the next shot around the world and arrest a couple of IRS agents.' We sincerely regret the error."

Mack filed a defamation suit against the center in December 2011, which he hopes will be adjudicated this summer.

If elected, Mack said he'd retire after four terms. "Lamar Smith is what happens when good people stay in Washington, D.C. for too long. Eight years was good enough for George Washington, it's good enough for Lamar Smith, and it's certainly good enough for me."

Mike Riggs is an associate editor at Reason magazine. Follow him on Twitter.