Sen. Heidi Heitkamp and her Republican rival, Rep. Kevin Cramer, agree there's a need for compassion for children separated from their families at the southern border. But their stances have included some differences and some barbs tossed at one another, and it's being noticed by voters in the northern border state.

Thousands of children have been separated from their families at the southern border under the Trump administration's "zero tolerance" immigration policy. President Donald Trump on Wednesday signed an executive order ending the process , after days of debate in the political arena.

Heitkamp, a Democrat whose seat Republicans see as one of their top pickup chances this fall, has focused more on the human element. She highlighted in social media posts the fact she's a mother, noting her support of the proposed Keep Families Together Act and even linking to a column by Laura Bush in which the former first lady says the separation of children and their parents "breaks my heart."

"My heart aches when I think about the trauma kids experience when they go to bed at night without the warmth and comfort of a parent's hug," Heitkamp said in a statement Monday. She also stressed the need to strengthen the country's borders but added, "separating kids from their families is cruel, unnecessary and inhumane. "

Cramer, a staunch Trump supporter, has spotlighted the need for immigration reform and border security, and accused Democrats of politicizing the family separation issue.

"Democrats must set aside their political ambitions and work with Republicans to fix our broken immigration system and secure our borders," he said. "Only then will we truly address the problem in a way that prevents separation of children from their families, respects the law of the land and protects the American people."

The slight difference in tone of the two candidates reflects their parties' positions and their personal natures, said Mark Jendrysik, chairman of the University of North Dakota's political science department.

"I think they're both trying to thread the needle," he said. "God forbid you appear to be lax on border security, but God forbid you appear to be in favor of tearing babies away from their moms."

Kevin Hildremyr, wearing a T-shirt with the phrase "Freedom Is Not Free" on it, said he supports the idea of keeping immigrants from coming into the United States illegally. But he doesn't see it as a major issue in the Heitkamp-Cramer race.

"I'm kind of leaning toward Heitkamp because she's doing what she's supposed to be doing," said Hildremyr, 52, of Fargo.

Rob Olson, a 50-year-old Cramer supporter from Fargo, said he believes Cramer would do a better job of strengthening the borders.

"I've seen some of Heidi's ads where she says she's not going to follow the party line," he said. "But you have to take advertising with a grain of salt."

Retired nurse David Gausman, 63, of Fargo, said the border issue cemented his vote for Heitkamp.

"I understand the immigration issue. We don't want people coming across the border," Gausman said. "But it goes against every molecule in my body that we break up these families, and these little kids are being torn away from their families."

Vern Smith, an 87-year-old retired railroad worker who lives in West Fargo, said the image of taking children away from their families is going to hurt Trump.

"And if it's going to hurt him, it's going to hurt Cramer," Smith said. "But I am Democratic. I like Heidi."

North Dakota's Democratic-NPL Party has sharply criticized Cramer on the issue, accusing him of "paying lip service to compassion" and calling him a "heartless politician." They pointed to comments he made on two radio programs Wednesday in which he pushed back on the idea that keeping border-crossing children in chain-link enclosures was inhumane. He said there was nothing inhumane about chain-link fences, noting they are "around playgrounds all over America, all over North Dakota."

Jendrysik said the Democratic message isn't likely to greatly influence voters, as "you can only get so far saying someone is heartless when they're not actually the one doing the thing."

Cramer campaign spokesman Tim Rasmussen on Wednesday said: "Kevin has repeatedly said we must always show compassion in the enforcement of our immigration laws especially when dealing with children who are often innocent bystanders. Kevin's comments on the radio today in no way contradict that position."

Rasmussen added that Democrats want to distract voters from issues such as Heitkamp's support of the Keep Families Together Act, which he claimed could result in a criminal arrested in much of North Dakota "getting off scot-free because he has children traveling with him," and said it "could actually encourage criminals to use children as shields to prevent arrest."

University of North Dakota associate law professor Kit Johnson, who specializes in immigration law, said the critique "is not accurate at all."

Heitkamp campaign spokeswoman Julia Krieger said the bill "would have as much impact on the federal government's ability to arrest and prosecute adults as (Cramer) has shown empathy to these traumatized children — zero."