Republican presidential candidate Ben Carson told Arizonans that if elected president, he would seal the entire U.S.-Mexico border with a double-fenced wall within a year of taking office.

His statement came in response to a question asked during a live half-hour telephone town hall meeting:

“How practically and quickly can we get a wall that’s effective?” one man asked, adding with great emphasis that “time is not on our side.”

Carson paused for moment, as if considering the logistics of constructing a 2,000-mile wall, before answering:

“I think it can be done in a less than a year,” he replied in his typical calm and steady manner.

The former neurosurgeon and GOP front runner among Republican Arizonans provided no specifics — no information on how much such an operation would cost, much less how he would persuade Congress to approve and pay for it — except to say that it would be a big job creator.

So would beefing up Border Patrol presence, he mentioned no fewer than three times.

In response to another question about illegal immigrants, Carson said: “We can secure the border in less than a year, but along with doing that, we have to eliminate what I call ‘the goodies’ — the benefits people can get if they’re here illegally.”

In fact, he spent much of his allotted half-hour answering what essentially amounted to the same question over and over again:

“What are you intentions for securing the southern border?”

“How would you seal the border?”

“What will you do to bring sanctuary cities to a stop?”

“What’s the probability of ISIS agents infiltrating the border? And what’s your plan for addressing the problem?”

Indeed, there was only one non-border-related question during the entire town hall, and it came from a woman who announced she recently had gotten into a Twitter war with someone claiming to be frightened by Carson’s religious fervor. She wanted to know how he responds to people who say he’s too religious.

His answer consisted largely of a strange joke about how such people can give him all of their money since U.S. currency says “In God We Trust.” The joke flopped.

If before this town hall Carson wondered whether stemming the tide of undocumented immigrants is the only thing conservative Arizonans care about, he’s probably sure it is now.

For the record, the town hall was sponsored by the Arizona Security and Prosperity Project and moderated by Fox News darling and Pinal County Sheriff Paul Babeu, whom the group describes as a “border expert.”

Babeu certainly had plenty to say about the problems of illegal immigration, and he had no shortage of praise for Carson — they both spoke nostalgically about the trip Carson made to the Arizona-Mexico border earlier this summer with Babeu as his tour guide.

“I don’t think it’s an impossible thing for us to shut down the border and gain control of it,” Carson said to Babeu at one point. “It’s just [that federal government lacks] the will to do it.”

Carson called for motion detectors, drones, a much larger Border Patrol presence, and an end to what he describes as a “catch-and-release” policy for first-time border-crossing offenders. He also railed against the Obama administration, heroin trafficked across the border, and citizens who support sanctuary cities.

“The whole concept of sanctuary cities goes against the grain of common sense,” he said. “In a Carson administration, any sanctuary city would suffer extremely tough penalties financially. We would eventually starve them out.”

He ended his talk, as politicians tend to do, by praising his audience:

“I always love coming to Arizona [because] it’s one of the few places where people have common sense and are brave. So to those people living along the border, hang on there, because help is on the way.”

