Tea Party favorite Rep. Steve Stockman (R-TX) has filed to run in a March primary against John Cornyn, the No. 2 Republican in the U.S. Senate.

In an interview with World Net Daily, Stockman said he was mounting his primary challenge because the Texas senator did not stand with Sen. Ted Cruz (R-TX) during the government shutdown. “We are extremely disappointed in the way he treated his fellow congressmen and broke the 11th Commandment and undermined Ted Cruz’s fight to stop Obamacare,” Stockman said. “And now it looks like Cruz was right and Cornyn was wrong. [Cornyn] sided with the president, essentially, in making sure Obamacare became law while Cruz did everything possible to stop it.”

In a statement late Monday night, Stockman attacked his opponent, the Republican minority whip, as a left-winger. “You and I are in a foxhole fighting to save this constitutional Republic, but liberal John Cornyn is bayoneting us in the back,” Stockman said. “Liberal John Cornyn betrayed Ted Cruz and worked with Harry Reid to fund Obamacare.” The Texas congressman went on to link himself to Tea Party favorites such as Cruz and Sen. Rand Paul (R-KY) while calling Cornyn “Harry Reid’s Republican.”

Stockman is in his second term in Congress, having served one term after the Republican wave of 1994 and then lost a reelection bid. He spent 16 years outside Congress before being elected in 2012 to the House seat vacated by Ron Paul.

Since his return, Stockman has made a name for himself with a wacky Twitter account that frequently engages in what can only be called trolling. The congressman also has been a forceful advocate for conservative issues such as gun rights, to a degree that one writer called his election “the closest his state ever came to electing a gun.” And Stockman is on the record opposing the Violence Against Women Act, telling Betsy Woodruff of National Review: “it’s called a women’s act, but then they have men dressed up as women, they count that. Change-gender, or whatever. How is that—how is that a woman?” The congressman has garnered yet more attention for his refusal to vote for John Boehner’s reelection as House speaker and his push for President Obama’s impeachment.

And that’s not all. Cornyn’s new challenger has grabbed headlines with a variety of personal issues. He was once arrested by police with Valium pills in his underwear and has recently come under scrutiny for failing to file legally required financial disclosure forms with the Federal Election Commission. In addition, during his 16 years outside Congress, he filed for bankruptcy and was subject to a tax lien for failing to pay an employee.

Still, Stockman could receive support in his primary bid from some major conservative groups. In a statement, Matt Hoskins, executive director of the Senate Conservatives Fund, hinted that his group might back Stockman. “We haven’t decided yet whether we will endorse Steve Stockman, but we’re excited about the potential here,” he said. “Texas deserves two conservative fighters in the Senate, not just one. John Cornyn has voted to increase the debt, raise taxes, bail out Wall Street banks, and fund Obamacare. He’s part of the problem in Washington, and voters deserve an alternative.”

By contrast, Cornyn, who served as the Lone Star State’s attorney general before being elected to the Senate in 2002, is a far less colorful character. Described by The New York Times as having a “visage that looks more British tea-sipper than Texas two-stepper,” he is a quintessential establishment Republican. Although he has built a conservative record on Capitol Hill, he has long been viewed with skepticism by many Texas conservatives. Indeed, Cruz, went out of his way to avoid backing his fellow Texas senator in a potential primary several months ago. In response to a question about Cornyn, Cruz said, “I think it is likely that I am going to stay out of incumbent primaries across the country, either supporting incumbents or opposing incumbents.” In a statement to The Daily Beast on Monday night, a Cruz spokesperson reaffirmed that “the senator’s likely staying out of incumbent primary races.”

However, the National Republican Senatorial Committee is rallying behind the incumbent. In a tweet posted an hour after Stockman filed to run on Monday night, NRSC spokesman Brad Dayspring wrote: “We are proud to support Sen. Cornyn and while this primary challenge is quite the head scratcher, it will be defeated.”

Texas holds its Senate primary on March 4, 2014.