Judge says Arizona can enforce most contentious part of immigration law

By Bill Mears, CNN Supreme Court Producer

(CNN) - A federal judge has allowed Arizona to enforce the most controversial part of its politically charged immigration law, the so-called "show me your papers" provision.

In an order on Tuesday, U.S. District Judge Susan Bolton upheld the section allowing authorities, while enforcing other laws, to question the immigration status of people who may be in the United States illegally.

The Supreme Court in June tossed out most other aspects of the tough new law, but said the part known by critics as the "show me your papers" provision could go into effect, at least for now.

The hot-button immigration issue is a major attack line in this year's presidential campaign with Republicans, led by Mitt Romney, accusing President Barack Obama of failing to devise a comprehensive strategy to deal with illegal immigration.

Arizona is the nation's most heavily traveled corridor for illegal immigration and smuggling. The Justice Department said Arizona's population of two million Latinos includes an estimated 400,000 there illegally, and 60% to 70% of deportations or "removals" involve Mexican nationals.

The Pew Hispanic Center recently issued a report that found that Mexican immigration to the United States has come to a standstill. However, the debate continues as more than 10 million unauthorized immigrants - from Mexico and other countries - continue to live in the United States.