Greg Brannon on Principles & Values

Tea Party supporter of constitutional conservative fighters

"We're facing the greatest threat to liberty in our lifetime," Brannon tweeted shortly after he filed at the State Board of Elections in Raleigh. "Now is not the time for go-along-to-get-along Republicans."

While Brannon's candidacy wasn't announced publicly before Monday, he's been criticizing Burr on his Facebook page. "Senator Richard Burr has repeatedly refused to take on President Obama and the Democrats in Washington, but boy does he love to undercut and smear constitutional conservative fighters like Senator Ted Cruz at every opportunity," he wrote last week.