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The Lone Star State endorsement marks one of Cruz's most high-profile backers and aims to give his campaign a much-needed boost just one week before the crucial, first-in-the-nation caucuses in Iowa.
"Of those individuals who have a chance to win the Republican primary, at this juncture, from my perspective, Ted Cruz is by far the most consistent conservative in that crowd," Perry told Politico on Sunday night. "And that appears to be down to two people."
Perry, who gave up his own unsuccessful presidential bid in September after just 97 days on the trail, had been plagued by stagnant polling and lackluster fundraising.
The former Texas governor had been a vocal critic of Trump, especially during the final weeks of his campaign, calling the billionaire a "cancer on conservatism" and bashing his "nativist appeals."
"He knows he's going to surround himself with people who do have that experience, and I'm very satisfied that on Day 1, he will be ready to be commander-in-chief," Perry told Politico.
Cruz's campaign has suffered blows in Iowa over the last week. His leading rival Donald Trump locked up the endorsement of 2008 vice-presidential nominee and former Alaska Gov. Sarah Palin in a memorable speech last Tuesday.
Sen. Marco Rubio, currently in third in recent Iowa polling, nabbed the coveted backing of the Des Moines Register newspaper, which has thrown its support behind the eventual Republican nominee since 1996.
And two recent Iowa polls have shown Trump stretching his lead to 11 percentage points in the Hawkeye State, with Cruz's advantage among evangelicals slipping away.
Trump also leads the Republican field by double-digits nationally and in the nation's second contest in New Hampshire, so his opponents see Iowa as a crucial state in which to stop the real estate mogul from gaining early momentum.
Cruz, who has received support from prominent conservative Glenn Beck, served as solicitor general during Perry's administration in Texas, but Perry originally backed his own lieutenant governor David Dewhurst over Cruz during his 2012 run for the U.S. Senate.
"I'd rather see folks come together, work together to find solutions, but from time to time, you've got to lay the marker down," Perry said when asked about Cruz's hardline stances.
Sen. Lindsey Graham, who also ended his 2016 presidential bid, has chosen to support former Florida Gov. Jeb Bush. Former GOP candidates Bobby Jindal, Scott Walker and George Pataki have yet to endorse.