PHOENIX (AP) -- Sen. Jeff Flake threw criticism back at President Donald Trump over his threats to shut down the government over border wall funding, questioning what happened to his frequent campaign pledge to make Mexico pay for it.
The president threatened earlier this week at a rally in Phoenix to shut down the federal government unless the gridlocked Congress agrees to build a border wall. Flake questioned the wisdom of constructing a wall in a landscape that includes flat desert, rolling hills, canyons, mountains and waterways — all of which present unique challenges in securing the border.
"This notion of a 2,000-mile wall has been — for anyone who spends time on the border — just out there, because there is so much of the border that simply doesn't lend itself to a wall of any type," Flake said.
He has been a target of recent criticism from Trump, who has expressed support for Flake's Republican primary challenger, former state Sen. Kelli Ward. Without mentioning Flake's name, the president criticized Arizona's junior senator during Tuesday's rally as "weak on borders, weak on crime."
Flake criticized the president's claim that the Mexican government would pay for a border wall.
"If you are saying we have to make good on this campaign promise (to build a border wall), I remember the campaign promise saying that Mexico was going to pay for it," Flake said. "And so all of a sudden that went away, and we're sticking with this. I have to find out what 'this' is. That hasn't been fully explained."
Flake commented about the president's call for a border wall after holding a Senate subcommittee hearing at the federal courthouse in Phoenix. The hearing was held to discuss proposals that would split up the U.S. 9th Circuit Court of Appeals, a longtime target of Republicans who say the court has a liberal slant, a high caseload and distances that are too far for judges to travel.
Flake said the median time last year for an appeal to the Ninth Circuit was more than a year — almost twice the national average.
"This is not a recipe for certainty or justice," he said. "With that kind of time between briefing and argument, the underlying law can very easily change before the case is even heard."
Sidney Thomas, chief judge for the circuit court, said he opposes splitting up the 9th Circuit because, in part, it would cause an increase in taxpayer costs because the courts would need more courthouses, law libraries and staff.
Thomas defended the circuit as frugal in renting office space. He also said the appeals court has enacted an effective system for triaging filings for any legal defects and has decreased the time it takes to process cases.
In discussing Trump's border wall after the hearing, Flake pointed out that he supported an ultimately unsuccessful 2013 measure that would have provided money for hundreds of miles of fencing and increased the number of agents serving in the U.S. Border Patrol. In the end, the measure failed.
In a phone call with Mexican President Enrique Pena Nieto one week after Trump was inaugurated, the US president acknowledged that both leaders were "in a little bit of a political bind" because each had vowed not to pay for the wall, according to a transcript of the call published earlier this month by The Washington Post.
The US-Mexico border currently has 654 miles of fencing. It's about one-third the length of the Great Wall of China. Nearly half of the fence sits in Arizona.