SIOUX FALLS, S.D. (AP) — South Dakota Gov. Kristi Noem announced Tuesday that she will join a growing list of Republican governors sending law enforcement officers to the U.S. border with Mexico.

Noem’s announcement that she will send up to 50 South Dakota National Guard troops to Texas comes as the GOP ramps up a political fight with President Joe Biden over border security. The issue has drawn a host of prominent GOP figures: former President Donald Trump was expected to travel to the border this week and Republican governors from FloridaNebraska and Iowa have all committed to sending law enforcement officers for border security.

Texas Gov. Greg Abbott this month announced plans to build more barriers along the border.

Abbott’s new push has been criticized as political theater, but he has defended the plan, saying the number of border crossers remains high. The governor said he will use $250 million in state money and crowdsourced financing for the barriers, although the timeline and cost for the push are unclear. It also faces potential court challenges from the federal government.

Large numbers of migrants have been showing up at the U.S. border with Mexico, with many turning themselves over to U.S. Border Patrol agents in seeking legal asylum status. But the numbers of families and children traveling without their parents crossing into the U.S. have dropped sharply since March and April, while the encounters with single adults have remained high.

A private donation will fund the cost of sending the South Dakota National Guard troops, Noem said. The deployment is expected to last from 30 to 60 days, while the other states involved are sending law enforcement officers for roughly two-week stints.

Noem, who is seen as a potential presidential contender, drew a distinction between her decision to send the National Guard and other governors who are sending state police officers.

“The border is a national security crisis that requires the kind of sustained response only the National Guard can provide,” she said in a statement. “We should not be making our own communities less safe by sending our police or Highway Patrol to fix a long-term problem President Biden’s Administration seems unable or unwilling to solve.”

The governor’s spokesman Ian Fury said the donation for the deployment came from Willis and Reba Johnson’s Foundation. Willis Johnson, a Tennessee-based founder of an online used car auction called Copart, regularly makes large contributions to Republicans, including $200,000 to the Trump Victory Committee last year.

Fury said “the governor welcomes any such donations to help alleviate the cost to South Dakota taxpayers,” but declined to provide estimates on the cost of the deployment, citing “security reasons.”

However, Democratic state Sen. Reynold Nesiba said the fact Noem was using a donor to pay for the deployment showed it was not a “ real priority” for the state, but instead gave her “political cover.” He said he was looking into whether using a private donation to fund the deployment is legal.

“This could set a dangerous precedent to allow anonymous political donors to call the governor and dispatch the Guard whenever they want,” he said.

Meanwhile, Arkansas Gov. Asa Hutchinson said he has declined a request from Texas to provide state troopers. Hutchinson said sending National Guard troops was still an option and has asked the adjutant general of the Arkansas National Guard to evaluate that possibility.

“Because of the public safety needs we have here in Arkansas and because of the important work they’re doing here, I will not be sending the Arkansas State Police to the border,” he told reporters.