Ted Robbins

The Arizona Legislature is debating whether to extend Medicaid to about 300,000 people in the state. The expansion is a requirement to get federal funding under the Affordable Care Act.

The big surprise is who has been leading the charge: Republican Gov. Jan Brewer. She's one of President Obama's staunchest critics and has confounded conservatives in her own party by supporting the expansion.

Google the words "Brewer" and "Obama." You'll get a now-famous image of Brewer wagging her finger at the president on the tarmac last year when she met him in Phoenix.

The runways at Fort Huachuca, Ariz., are busy. This is where the Army tests its military drones, where it trains its drone pilots, and where four Customs and Border Protection drones take off and land.

From here, the CBP drones survey the Arizona-Mexico border — mainly looking for immigrants and drug smugglers.

Some employers around the nation have been using E-Verify to check the immigration status of employees for years. Operated by the Department of Homeland Security, the online system is designed to make it harder to hire unauthorized workers — and harder for those workers to find jobs.

While participation in the program has been voluntary since 1996, the immigration bill now in the Senate would make E-Verify mandatory.

Nearly half the people now in the U.S. illegally didn't climb walls, wade across the Rio Grande or trek through the desert to get here. They arrived legally, with tourist or student visas. And when those visas expired, they just never left.

Like the rest of the 11 million undocumented people in the United States, they are part of the underground economy and the government doesn't know where they are. The Senate immigration bill now before Congress tries to address this problem — though not as richly as it does border security.

Budget-cutting from the government sequester that began March 1 could affect U.S. exports and imports, including what we eat.

Customs and Border Protection officers regulate trade at the nation's 329 ports of entry, in harbors, airports and on land.

One by one, drivers approach booths with Customs and Border Protection officers at the Mariposa Port of Entry in Nogales, Ariz. More winter produce enters here than at any other place in the U.S. Semis filled with tomatoes, cucumbers and peppers headed to grocery stores around the country.

In the back and forth between Congress and the White House over immigration, both sides seem to agree that people now in the U.S. illegally should wait at "the back of the line" for legal residency — meaning no green card until all other immigrants get theirs.

But that presents a problem, because the wait for a green card can take decades.

Maria has been waiting in line with her husband for 16 years and counting for what the government calls a priority date for legal residency. Because she is in the U.S. without documents, Maria asked NPR to use only her first name.

Half of all tomatoes eaten in the U.S. come from Mexico, and tomato growers in Florida aren't happy about that. In fact, they're willing to risk a trade war to reverse the trend.

At JC Distributing In Nogales, Ariz., one misstep and you're likely to get knocked over by a pallet full of produce. Forklifts crisscross each other carrying peppers, squash and especially tomatoes from trucks backed into the warehouse loading dock.

"This is a Mexican truck being unloaded," says JC President Jaime Chamberlain. "He's just waiting for his paperwork to get back."

Brad Holland had big plans for the empty lot he owns in midtown Tucson, Ariz.

"This was going to be my dream house before the economy collapsed," Holland says. "I had a big empty lot and said, 'Wow, a lot of good can come out of this.' "

Since the mid-1980s, the U.S. Border Patrol has quintupled in size — growing from about 4,000 to more than 20,000 agents.

The government has constructed some 700 miles of fencing and vehicle barriers. It has placed thousands of ground sensors, lights, radar towers and cameras along the border. And Customs and Border Protection is now flying drones and helicopters to locate smuggles and rescue stranded immigrants.

So here's the question: Is the Southwest border secure?

Congress is considering whether to turn three top-secret sites involved with creating the atomic bomb into one of the country's most unusual national parks.

The Manhattan Project — the U.S. program to design and build the first atomic bomb during World War II — largely took place at three sites: Los Alamos, N.M.; Oak Ridge, Tenn.; and Hanford, Wash. On July 16, 1945, the first test of an atomic bomb took place at a site in the southern New Mexico desert. Hiroshima and then Nagasaki, Japan, were bombed less than a month after the test.