Ted Cruz announced Wednesday he will tap Carly Fiorina to be his running mate if he is the Republican Party's presidential nominee, praising her as a fierce competitor "not intimidated by bullies" who has "shattered glass ceilings" in both business and politics.
"It is unusual to make the announcement as early as we are doing so now," Cruz said at a rally to announce his pick in Indianapolis. "Well I think all would acknowledge that this race, if anything, is unusual."
Fiorina, a former HP CEO who highlighted her business background during her own 2016 run, dropped her unsuccessful White House bid in February. She endorsed Cruz one month later and has been a frequent surrogate for him on the campaign trail.
"Today I am very proud and very humbled and honored to announce that I have accepted Sen. Ted Cruz's offer to be his vice president for the Republican nomination," Fiorina said after Cruz's lengthy introducation.
The announcement comes one day after Cruz was officially mathematically eliminated from winning the Republican nomination by capturing a majority of GOP delegates. Cruz's camp argues that Trump will fail to reach the 1,237 delegates needed to secure the nod and that delegates will pick instead Cruz as an alternative candidate during the Republican National Convention in Cleveland.
"So why make this announcement now? Well, for one thing, if we are to win...We must unite," Cruz said. "And Carly as vice presidential nominee who I believe is superbly skilled, superbly gifted at helping unite this party, bring us together, so we stand united as one."
The move is designed to give Cruz a burst of desperately-needed momentum after Trump walloped his rivals in Tuesday's primary contests in five northeastern states. While the real estate mogul is still short of enough support to be formally named the party's presumptive nominee, Cruz will need a significant win in Indiana's May 3 primary to maintain momentum for his anti-Trump movement. He would also need a strong performance in the June 7 primary in California, where Fiorina mounted an unsuccessful bid for Senate in 2010.
Among the many Fiorina accomplishments Cruz highlighted in his announcementment was his former rivals showdown with Trump during a debate last year after he brought her personal appearance into the GOP primary race. And she has continued to serve as an attack dog against Trump since endorsing Cruz.
"It isn't over because you and people all across the great Hoosier State and people all across this nation know that Donald Trump and Hillary Clinton both will be disasterous for this nation," Fiorina told the Indiana crowd.
NBC News confirmed earlier this week that Cruz was vetting Fiorina for the position.
For weeks, Fiorina has tried to thwart suggestions that her endorsement of Cruz in early March was part of a plan to join his administration.
"This isn't about a deal," she told a roomful of supporters in Fond du Lac, Wisconsin, last month.
Last month at a Milwaukee lunch stop, Cruz, sitting next to Fiorina, suggested to reporters that Fiorina would make "an incredible VP."
The former CEO and presidential candidate jumped into the conversation, interjecting: "Let's get him the nomination first. The media keeps jumping ahead."
While Fiorina's presidential bid faltered, she was viewed as a tenacious debater who used strong performances in "undercard" televised debates to muscle her way into the far more widely viewed primetime clashes.
Since campaigning alongside Cruz, Fiorina has also taken on the role as his chief defender.
When Cruz faced questions over allegations of infidelity in a National Enquirer story, Fiorina jumped in to answer a reporter's question, jumping in: "If I may—"
She followed up by, unflinchingly, by calling Trump "a serial philanderer."
Fiorina told NBC News at the time that she feels she can "help him out" when "absurd" questions from the media are directed his way.
"Let's face it - sometimes the questions that the media asks are absurd, and as you have come to know me on the campaign trail, I don't shy away from taking it on," Fiorina said at the time. "So there are times when I think someone other than Ted can say things that he can't say. And in that particular case, it was just an outrageous, absurd question."
Cruz's decision to select a running mate without securing the nomination would not be without precedent. Ronald Reagan famously announced Sen. Richard Schweiker would be his running mate heading into the open convention in 1976.
This article first appeared on NBCNews.com.