Hillary Clinton's vice presidential running mate Tim Kaine was quick to show off his Spanish-speaking ability just after being introduced at FIU in Miami on Saturday, July 23. (Reuters)

This year’s fight to become vice president included talk in both parties about the age, gender, height, weight and marital history of various contenders. On the Democratic side, it also focused for the first time on whether certain potential running mates could speak Spanish.

Presidential candidate Hillary Clinton considered two Latino contenders for her running mate, Housing and Urban Development Secretary Julián Castro and Labor Secretary Thomas Perez, and ultimately chose Sen. Timothy M. Kaine of Virginia, in part because he is fluent in Spanish.

That linguistic mastery factored in at all is a testament to the growing clout of the Hispanic electorate. But the idea that Castro and Perez would have struggled to woo Latino voters because they do not speak Spanish as confidently as Kaine — a notion advanced primarily by non-Hispanic news organizations and political consultants — reflects a deep misunderstanding of the fast-growing voting bloc.

Such talk “drives me nuts,” said Chuck Rocha, a Democratic political consultant who was a senior adviser to the presidential campaign of Sen. Bernie Sanders of Vermont.

A self-described “third-generation Texas Mexican,” Rocha said that Clinton’s decision to pass over Castro and Perez stung because “I was looking for a VP choice that showed my son that one day he could be president — not that he needs to work on his Spanish.”

Secretary of Housing and Urban Development Julian Castro, left, and Labor Secretary Tom Perez. (AFP/Getty Images, AP/AFP/Getty Images, AP)

He added, “Remember, we are talking about Latino voters — not the general population, and the vast majority of Latino voters do not speak Spanish as a first language.”

Castro, a Mexican American, and Perez, a Dominican American, grew up in pockets of the country where Spanish is not necessarily the norm. Kaine, who was born in Minnesota and is a Virginia politician, learned Spanish while serving as a missionary in Central America.

To be sure, Kaine won the vice-presidential slot for non-linguistic reasons. Amid a wave of terrorist attacks in the United States and abroad, Clinton deemed national-security and foreign-affairs experience critical. Those are big professional blind spots for Castro and Perez, but Kaine’s Senate term has included time on the Armed Services and Foreign Relations committees. His term as Virginia’s governor also gives him significant executive experience.

Introduced by Clinton to a predominantly Hispanic crowd in Miami on Saturday, Kaine beamed as he delivered several dutiful lines in “Spanglish.”

He said that he and Clinton would be “Compañeros de alma in this great lucha ahead” — soul mates in this great fight ahead. While serving as a missionary in Honduras, he said, “Aprendí los valores de mi pueblo: fe, familia y trabajo. Los mismos valores de la comunidad latina aquí” — I learned the values of my town: faith, family and work. The same values of the Latino community here.

“Soy católico,” he added — I’m Catholic — the religion of most Hispanics in the United States.

Labor Secretary Tom Perez greets attendees of a women's summit at the Department of Labor on June, 15, 2016 in Washington. (Bill O'Leary/The Washington Post)

But nearly 7 in 10 Latinos said that a candidate’s fluency in Spanish will not affect their vote, according to a poll conducted last year for the Spanish-language network Univision. Barely a quarter said it will.

An overwhelming majority of Latinos — 95 percent — say it is important for future generations to speak Spanish, but 7 in 10 Latino adults do not think it is necessary to speak the language to be considered Latino, a Pew Research Center study released in February found.

Analyzing U.S. Census Bureau data, Pew determined in January that Hispanic millennials are poised to make up nearly half of the nearly 28 million eligible Hispanic voters expected to cast a ballot in November. These younger voters do not just watch Univision, listen to Spanish music or play soccer. They dominate school systems in Arizona, California and Texas and increasingly dominate pockets of Georgia, Massachusetts, North Carolina and Rhode Island.

For younger Hispanics — such as this reporter — speaking Spanish is not a litmus test for “Latinidad,” or Latin identity. Being Hispanic is increasingly about growing up in certain kinds of communities and understanding what it is like to have one or two immigrant parents and roots in more than one country. Many Latinos call the struggle “nideaquinidealla” — a term that strings together several words and means “not from here, nor from there.”

Perez, 54, grew up in Buffalo, far from larger centers of Hispanic activity in the 1960s. He occasionally speaks Spanish in public — sometimes delivering Spanish versions of President Obama’s Saturday morning radio address.

Castro, 41, grew up in San Antonio as a multi-generational Mexican American, a subgroup that is less likely to speak Spanish at home, given its deeper roots in the United States. On the stump, Castro might quickly speak a few words in Spanish, but he does not do Spanish-only interviews.

Because of his higher profile, Castro’s language skills came under intense scrutiny during the vice-presidential guessing game. In a profile that Politico published last year, a Democratic operative claimed anonymously that “Tim Kaine speaks Spanish much better than Julián Castro does.” The New York Post gossip pages claimed in May that Castro and his twin brother, Rep. Joaquin Castro (D-Tex.), were “cramming with Rosetta Stone,” software for learning languages. They angrily denied the charge.

Freddy Balsera, a Miami-based political consultant who crafted Spanish-language advertising for Obama’s 2008 campaign, said that for candidates, just speaking Spanish, if they do not share the same priorities as Hispanic Americans, is “part pandering.”

“Gaining our support isn’t as shallow as saying ‘hola,’ playing some maracas and passing out tacos,” he said. “That is precisely why Hispanic political prominence has become so meaningful. We are making candidates work for our vote.”

“It would have been a great source of pride to have a Hispanic on the ticket, but it is not just about that,” he added, recalling that Republicans had a chance to nominate Sens. Ted Cruz (Tex.) and Marco Rubio (Fla.), who both speak Spanish, or former Florida governor Jeb Bush, who learned to speak the language fluently from his Mexican American wife.

“I am positive that they would have had serious difficulties with Hispanic voters despite their heritage,” Balsera said.

That is a reference to the GOP’s opposition to comprehensive immigration reform and increasingly absolutist stance on constructing a wall along the U.S.-Mexico border. The party also nominated Donald Trump, despite his attacks and mockery of Latino government officials and Mexican immigrants.

Ana Navarro, a Nicaraguan-born former adviser to Bush and Sen. John McCain (R-Ariz.), tweeted on Friday that Clinton had chosen Kaine, a “Spanish-speaking do-gooder who was a missionary in Honduras.” Trump’s Hispanic outreach, she tweeted, included the support of Joe Arpaio — an ardently anti-immigrant Arizona sheriff — and “a taco bowl,” referring to a controversial tweet Trump sent on Cinco de Mayo.

“Make no mistake about it,” Navarro tweeted Saturday, for Hispanics, Kaine “will be a hell of a good surrogate” for Clinton. “He gets it.”

In 2013, Kaine, 58, became the first U.S. senator to deliver a Senate floor speech entirely in Spanish to voice full support for a comprehensive immigration-reform bill.

“As somebody who lived in Latin America and has a real passion and attachment to the immigrant story — latinos y otros, porque hay un gran número de asiáticos y otros en Virginia — it’s something I had been looking forward to doing,” Kaine told The Washington Post after the speech, using Spanish to say, Latinos and others, because there’s a large number of Asians and others in Virginia.

He joked in the interview that despite his strong Spanish diction, “I’m definitely a gringo.”