"We are extremely disappointed in the way he treated his fellow congressmen and broke the 11th commandment and undermined (Sen.) Ted Cruz's fight to stop Obamacare," Stockman told WND.com.
Stockman filed his candidacy for Cornyn's seat at 5:45 p.m. on Monday, just before the 6 p.m. filing deadline, according to the Houston Chronicle.
Stockman was first elected to Congress in 1994 and then lost reelection. He was elected a second time in 2012. Cornyn, a former Texas district judge and Texas attorney general, was first elected to the Senate in 2002. He won reelection in 2008.
Cornyn had gone to considerable lengths to prevent a tea party favorite like Stockman from running against him in the Republican primary. In July, the senior senator from Texas hired Brendan Steinhauser, formerly the director of campaigns for the pro-tea party FreedomWorks, to run his campaign. Cornyn has also run campaign ads highlighting his conservative record in order to prevent someone like Stockman from accusing him of being insufficiently conservative. That wasn't enough for Stockman though.
In his announcement Stockman went on to criticize Cornyn for opposing Sen. Ted Cruz's (R-TX) effort to fund the government only if Obamacare is defunded.
"And now it looks like Cruz was right and Cornyn was wrong," Stockman said, adding that Cornyn "sided with the president, essentially, in making sure Obamacare became law while Cruz did everything possible to stop it."
Cornyn has defended his opposition to Cruz's approach as a tactical disagreement. The No. 2 Senate Republican has stressed that he strongly opposes Obamacare but there are other ways to fight the law.
"If you disagree with someone, that's fine, but I really believe you should do it privately, not so publicly," Stockman said. "He made a big show of removing his name from a letter supporting Cruz."
Stockman's decision to run against Cornyn will make the race for Cornyn's Senate seat a major stage in the so-called Republican civil war between the tea party and establishment wings of the GOP. It also means that the top two Republicans in the Senate -- Mitch McConnell (R-KY), the minority leader, and Cornyn, the minority whip -- are facing significant primary challengers in their reelection bids. Cornyn was the chairman of the National Republican Senatorial Committee, charged with getting Republicans elected to the Senate, from 2009 until earlier this year.
The National Republican Senatorial Committee was quick to stand by Cornyn. NRSC communications director Brad Dayspring called Stockman's decision a "head scratcher."
"John Cornyn is one of the most conservative Members in the Senate and strong leader for the state of Texas," Dayspring said in a statement. "We are proud to support Senator Cornyn and while this primary challenge is quite the head scratcher, it will be defeated."
In the hours after Stockman's announcement, aides for Cornyn had already begun calling attention to some of the likely weaknesses of Stockman's campaign. Drew Brandewie, a longtime Cornyn aide, noted over twitter that Stockman only has $32,027 cash on hand, a pittance compared to the $7 million war chest Cornyn has amassed toward his reelection campaign, according to Federal Election Commission filings.
"Stockman had $32,027 cash on hand and $163,010 in debt." http://t.co/3u8B10AHFn— Drew Brandewie (@DBrandewie) December 10, 2013