(Steve Helber/AP Photo)

With news of Tuesday's stunning tea party upset over House Majority Leader Eric Cantor still fresh, a tea party-aligned group is announcing a leadership appointment.

Ken Cuccinelli, the former Virginia attorney general and failed gubernatorial candidate, has joined the Senate Conservatives Fund as its new president, ABC News has exclusively learned.

SCF is an outside group which boosts tea party challengers over some Republican incumbents and is hated by many establishment Republicans such as Senate Minority Leader Mitch McConnell. It was founded by former South Carolina Sen. Jim DeMint.

In a statement, Cuccinelli said he is "honored" to join SCF and has "always had tremendous respect for this organization" and he "applaud(s) its members for working to elect principled conservatives."

In a video message to SCF supporters, Cuccinelli calls himself an "unwavering constitutional conservative" and said the group will continue to "stand up to the status quo, continuing to support conservative candidates wherever we find them, and, yes, that means continuing to take on Republican incumbents who've lost their way."

Cuccinelli adds: "Standing up to the establishment isn't easy, but it is the right thing to do if we are going to save our country."

Cuccinelli lost the Virginia governor's race in November to Terry McAuliffe.

SCF has backed the tea party challenger in the Mississippi Senate race, Chris McDaniel, who looks poised to beat incumbent Sen. Thad Cochran in a runoff, as well as Joni Ernst, who was backed by both establishment and tea partiers in the Iowa Senate race. The organization has spent over $6.5 million on races all over the country.

But SCF-backed candidates have also experienced some big losses recently, most notably Matt Bevin's defeat to McConnell in last month's Kentucky GOP Senate Primary.

Tea party groups were quick to congratulate Cantor's opponent, Dave Brat in his upset victory. The win is sure to embolden and excite tea partiers, but none of the outside groups - including SCF - were engaged beforehand, a sign that Brat's win shocked them, too.