In a sign that Sen. Ted Cruz is gathering steam in his quest to win the GOP nomination, former Republican presidential candidate Carly Fiorina endorsed the senator from Texas in a surprise announcement Wednesday.

During a rally in Miami Wednesday, Ms. Fiorina said that she didn't vote for herself in the Virginia primary last week on Super Tuesday, despite appearing on the ballot, but instead chose Senator Cruz.

"I checked the box for Ted Cruz and I am here to tell you why," the former Hewlett-Packard CEO said. “Ted Cruz is a fearless fighter for our constitutional rights. He has spent his life protecting Americans’ God-given liberties, and he has always stood by his word."

"My fellow conservatives … you have a very important job on Tuesday and I say to you it is time to take our party back," Fiorina continued. "It is time to take our government back. It is time to take our country back and so it is time now to unite behind the one man who can beat Donald Trump, who can beat Hillary Clinton. It is time to unite behind Ted Cruz."

Fiorina's endorsement "is likely to have modest impact, at best," says David Ryden, professor of political science at Hope College in Michigan, but with two important caveats.

"That she saw her name on the ballot and yet pulled the lever for Cruz gives the endorsement an authenticity that most lack," Professor Ryden says, adding, "Also the fact that the endorsement came in Florida could reinforce Cruz's seriousness about competing to win in that state."

Fiorina suspended her own presidential campaign in February after she failed to turn a few impressive debate performances into votes in early contests. Unlike New Jersey Gov. Chris Christie, who clashed with Mr. Trump during debates, only to endorse him after dropping out, Fiorina rarely, if ever, attacked Cruz while she remained in the race. In fact, her policy stances frequently mirrored his, including extremely conservative positions on abortion and abolishing the IRS.

While a surprise, her endorsement is a natural fit for the Cruz campaign, which stands to benefit from Fiorina's nod. Here's how:

It suggests Cruz can unify

It's no secret that Cruz has few friends among the GOP establishment, many of whom view the Texas senator as abrasive and divisive.

“If you killed Ted Cruz on the floor of the Senate, and the trial was in the Senate, nobody would convict you," Senator Lindsey Graham recently joked.

But the Republican establishment, increasingly desperate for a viable alternative to Trump, is warming to Cruz, who now has to attempt something of a rapprochement with his party in order to gain its support.

Fiorina's endorsement comes at a time when other Republicans are considering uniting around Cruz – another former 2016 contender, Rick Perry, endorsed him in January. The endorsement also helps Cruz, who is typically viewed as an alienating figure, present himself as a unifier.

In fact, Cruz himself immediately seized on the endorsement to suggest he was uniting the Republican Party.

"It's easy to talk about the party coming together," Cruz said. We're seeing manifestations of this."

She can be an anti-Trump surrogate

Fiorina, known for her strong debate performances, is well-spoken and may prove to be a strong surrogate for Cruz. She has long been a loud and vocal critic of Hillary Clinton, whom she attacked relentlessly during her campaign. And she has taken on Trump, with whom she famously tangled in a Republican debate last fall in one of the few moments that appeared to knock the outspoken billionaire off his feet.

She displayed her willingness to go after both in her endorsement.

“The truth is that Donald Trump and Hillary Clinton are two sides of the same coin,” she said. “They’re not going to reform the system, they are the system.”

She can bring more women into the Cruz camp

Women voters comprise 53 percent of the electorate in the general election, and the GOP has been known to perform relatively poorly with women in recent elections. President Obama won the female vote by 13 points in 2008 and 11 points in 2012

Cruz struggles with female voters, according to recent polls. He would also lose a general election to Democratic candidate Sen. Bernie Sanders because he would lose women by 16 points, according to this Quinnipiac poll. Female voters choose Florida Sen. Marco Rubio (R) 39 percent of the time, compared with only 23 percent for Cruz, according to Public Policy Polling.

That's because "he has painted himself as the most extreme conservative in the race," writes Hadley Heath Manning, a senior policy analyst at the Independent Women's Forum, for US News and World Report. "This branding and strategy affect his tone, which could be off-putting to many women."

"Meanwhile, in stark contrast, Rubio … and [Ohio Gov. John] Kasich [both] stress unity, optimism, inclusiveness and outreach," she writes. "In general … more women see these candidates as honest and trustworthy, and more women say these candidates care about the needs and problems of people like them."

Of course, Cruz's main rival, Trump, also has a significant gender gap with women, so it's possible Fiorina may help Cruz capitalize on that weakness by appealing to more women voters, says Ryden.

"I suppose there could be undecided female voters with old-fashioned sensibilities, for whom this reminds them of Trump's previous ill treatment of Fiorina and push them toward Cruz. Anything that continues to make folks more comfortable with the prospect of voting for Cruz certainly cannot hurt his cause."