Ron Paul, Sarah Palin, throw support behind tea party favorite Ted Cruz in Texas

Sarah Palin threw her voice into the Texas Republican Senate race on Thursday, endorsing tea party favorite Ted Cruz less than three weeks before the state's primary.

"We're proud to join conservatives in Texas and throughout the nation in supporting your campaign to become the next Senator from the Lone Star State," Palin wrote in a letter to Cruz, which was released by his campaign.

A former solicitor general, Cruz has been locked in a high-profile battle against Lt. Gov. David Dewhurst to fill the seat soon to be vacated by Sen. Kay Bailey Hutchison. Former Dallas Mayor Tom Leppert and ESPN broadcaster Craig James are also contenders in the race.

While Dewhurst has high name recognition as the longtime No. 2 to Texas Gov. Rick Perry, Cruz has shaped his campaign as being the conservative alternative to Dewhurst.

In Palin's endorsement, she highlighted what she called Cruz's "conservative principles" and "passionate defense" of the Constitution.

"Our shared goal isn't just to change the majority in control of the Senate, but to assure principled conservatives like you are there to fight for us," she said.

Republican presidential candidate and Texas Rep. Ron Paul also threw his support behind Cruz on Thursday, adding one more voice to a growing list of high profile endorsements for the candidate.

National conservative groups, including super PACS for FreedomWorks and Club for Growth, are also throwing money into the race. Both groups played a big role in the Indiana Senate primary battle, in which state treasurer Richard Mourdock ousted six-term Sen. Dick Lugar earlier this week.

On Wednesday, Club for Growth's super PAC announced a $1 million ad buy attacking Dewhurst.

Meanwhile, Dewhurst's team points to endorsements from former GOP presidential candidate Mike Huckabee, as well as Michael Reagan, son of former President Ronald Reagan.

The lieutenant governor also has the backing of Texas Right To Life PAC and several oil and agricultural groups.

Dewhurst also has a strong fundraising advantage over Cruz, with nearly $12 million raised this cycle compared to Cruz at just over $5 million, according to filings with the Federal Election Commission.