Get with it.

That was the bottom line of the message by the national Republican chairman to politicians in his party in an open letter on how to gain support among Latino voters.

In the letter, which appeared Wednesday in the National Review, Reince Priebus, chairman of the Republican National Committee, said candidates and office holders at every level of government had to make a greater and better effort to address Latinos in a way that would appeal to – and not continue to alienate – the community.

The stakes were too high, he said, to neglect Latinos.

“Hispanics are the fastest-growing demographic group in America,” he noted. “In the past decade they accounted for more than half of the nation's population growth, according to Pew Hispanic. No party can fully represent the American people if it doesn't build relationships with the Hispanic community.”

Hispanics are now the nation’s largest minority – 21 million of the ethnic community’s population of roughly 53 million are registered voters.

In last year’s presidential election, President Obama got 70 percent of Latino voters who cast their ballots.

The GOP challenger, former Massachusetts Gov. Mitt Romney, got 27 percent of the vote, which prompted soul-searching within the Republican Party. After the election, the RNC announced a multi-million dollar campaign to reach out to minority voters.

Part of Romney’s poor showing among Latino voters was blamed on the hard line on immigration and English as the official language that many of the candidates vying to be the party’s presidential nominee took during the primaries.

“In working to earn Hispanics' trust, though, Republicans have to remember that it's not just about what we say, but how we say it,” Priebus said. “Our principles are sound, but we have to be thoughtful in how we discuss them. Too often, a candidate's tone can turn off voters, promote divisiveness, and feed mischaracterizations of our party. So if your tone isn't welcoming and inclusive, you're doing it wrong.”

Romney in particular came under fire from some Latino leaders and immigration advocates for taking the most hard-line positions of all the candidates in GOP debates and in campaign speeches. He said he firmly opposed any measure or policy change that gives a break to undocumented immigrants.

One of his most controversial stances had to do with his support for “self-deportation,” where undocumented immigrants would find life in the United States so difficult that they would simply leave on their own.

Romney also opposed the DREAM Act, a proposed measure that would allow undocumented immigrants brought to the United States as children the chance to legalize their status if they attend college or serve in the military, among other things. He vowed that if the measure ever became law, as president he would veto it.

Beyond immigration however, many Latino voters also said they were put off by the Republicans’ opposition to the Affordable Care Act, which many Latinos have said they support.

“When we don't fight for the Latino vote, two things happen,” Priebus said in the open letter, which also acknowledged Hispanic Heritage Month, which runs from Sept. 15 to Oct. 15. "Some Hispanics sit out elections, which was the case in the last election, or Democrats take their votes for granted."

“In 2014 we're going to hold accountable vulnerable Democrats like Ron Barber, Raul Ruiz, Joe Garcia, Pete Gallego, and Patrick Murphy, to mention a few, who have failed their constituents, a significant number of whom are Hispanic."

Priebus’s open letter was met with skepticism.

D.A. King, who has led various campaigns in Georgia supporting tough immigration enforcement, said the RNC effort to court Latinos veered into an abandonment of principles that are important to conservatives.

"Along with John McCain, Marco Rubio and Paul Ryan, Reince Priebus is another example of why this conservative voter is not a member of any political party,” King said, referring to GOP lawmakers who have expressed support for giving legal status to undocumented immigrants.

“While the GOP hierarchy wrings its hands on how to improve voter turnout, it plays lapdog to the business community and the endless demands of ever-cheaper labor,” King said. “A process that not only hurts potential Hispanic GOP voters, but drives the remainder of the conservative base, including loyal Hispanics, into hiding at election time. Too many of us still remember the disastrous results of the one-time ‘immigration reform’ of 1986.”

But other critics of the open letter said it struck them as superficial, and missing the point of what alienates Latinos from the Republican Party.

“There are many positions on issues that the Republican Party supports that Latinos agree with," said Jimmy A. Hernández, communications director for Voto Latino. "But the Republican Party, regardless of how strong their outreach, will have a difficult time connecting with American Latinos as long as certain factions of the party continue to oppose immigration reform with a pathway to citizenship."

If the GOP helps move the ball forward on a pathway to legal status, Hernández said, "Countless polls have shown that Hispanics are ready to support the Republican Party."

Frank Sharry, who heads America’s Voice, a Washington D.C.-based group that pushes for less restrictive immigration policies, said the Republican party’s problems with Latinos go beyond tone, and are more centered on its policies.     

He specifically cited the opposition by many Republicans in Congress to support comprehensive immigration reform bills that would provide a pathway to legal status for the undocumented. Many Republicans in the House, where they have a majority, said that would be tantamount to “amnesty,” or rewarding lawbreakers.

“Just a few months ago, the RNC's autopsy called on Republicans to go beyond changing their tone to changing their policies,” Sharry said. “They specifically called on Republicans to support comprehensive immigration reform. Now the RNC Chairman has retreated to the idea that it's about showing up and tone.”

“When are they going to learn that mariachis and platitudes aren't going to work, but making sure immigration reform passes the Congress this year will?”

Elizabeth Llorente can be reached elizabeth.llorente@foxnewslatino.com

Follow Elizabeth Llorente on https://twitter.com/Liz_Llorente

Like us at facebook.com/foxnewslatino