An estimated 12.2 million Latino voters across the country will vote in this year's presidential election, but that falls far short of the number who are eligible, the head of a national organization recently told Valley Latino leaders in urging a voter-registration push.

Although that is a huge number, such turnout "is unacceptable," said Arturo Vargas, executive director of the National Association of Latino Elected and Appointed Officials, who spoke Friday at the annual breakfast for the Phoenix social- and health-services nonprofit group Valle del Sol.

"Why? Because in November there will be 22 million Latino voters who will be eligible to vote," Vargas said. "That means 10 million will stay home. We need to turn this around."

Vargas urged more than 300 Latino business and non-profit group leaders at Friday's breakfast for Valle del Sol to promote voter registration to ensure everyone who is eligible to vote can cast a ballot in the November elections.

Latinos are a targeted set of voters because they are the fastest-growing ethnic minority group in the United States -- and in Arizona. Census data show that Arizona gained 1.3 million new residents from 2000 to 2010, and 600,000 of them were Hispanic. Their share of the state's population grew from about 25 percent in 2000 to 30 percent in 2010. Vargas estimated that 396,000 Latinos are registered to vote in Arizona, a 23 percent increase from the Latino voters who cast ballots in the 2008 presidential election.