One of the hottest points of contention in the immigration reform debate is whether to offer immigrants a path to citizenship.
Some anti-citizenship Republicans have said that a legalization program will give the Democrats millions of new voters. The problem is, existing data suggests that those fears are likely overblown.
More importantly, the data shows that Mexican immigrants, who make up 55 percent of the undocumented population, are less likely to become citizens than other groups.
Only about one-third of the 5.4 million legal immigrants from Mexico who are eligible to become citizens have actually naturalized. That's about half the rate of naturalization among legal immigrants from all other countries, according to the Pew Hispanic Center.
That's not because Mexican immigrants aren't interested. Pew found that more than 90 percent of Hispanic immigrants who have not yet naturalized would like to. The obstacles, however, are sometimes too overwhelming.
More than a quarter said personal barriers such as a lack of English proficiency are a problem, while nearly 20 percent said financial and administrative barriers are preventing them from trying. The application fee is $680.
About a quarter said they have not tried or are not interested. Nearly a quarter said the citizenship test, which requires applicants to demonstrate knowledge of government and history, is too difficult.
Any immigration proposal is likely to include similar requirements. Even proponents of full citizenship rights for the country's 11 million undocumented immigrants advocate an English-language requirement and the payment of back taxes.
Alternatives to citizenship are still better than no legal status. Legal permanent residency -- a green card -- eliminates the threat of deportation and grants the ability to work. But green card holders can't vote or receive some other benefits such as a U.S. passport or the right to apply for most federal jobs or run for office.
Most Hispanic immigrants say, though, that they would like to become citizens. Some want this for practical reasons and others because the United States feels like home. According to the survey, Mexicans are more likely than non-Mexicans to give practical reasons for becoming citizens. Non-Mexican naturalized Latinos are more likely to name family and sentimental motivations as driving factors.
As Pew notes, the Immigration Reform and Control Act of 1986 was the last time the United States authorized a path to citizenship for undocumented immigrants, and Mexican immigrants were the main beneficiaries. But only about 40 percent of the 2.7 million undocumented immigrants who received a green card through IRCA were citizens by 2009.
The rates of naturalization among Mexican immigrants today is fairly similar.
In 2011, Mexican immigrants naturalized at a rate of about 36 percent compared to 68 percent for all non-Mexican immigrants. Latin American and Caribbean immigrants had a naturalization rate of 61 percent.