(CNN) President Donald Trump has repeatedly used the killing of 20-year-old college student Mollie Tibbetts as fuel for a new round of political attacks less than three months out from the midterm elections.

Republicans are increasingly following suit, both in Iowa, where authorities on Tuesday charged with Tibbetts' murder a man they say is an undocumented immigrant, and in other states where immigration policy could affect both primary and general election contests.

"What happened to Mollie was a disgrace, and our hearts go out," Trump said while speaking to Republicans in Ohio Friday.

After mentioning two other examples of crimes committed by an undocumented immigrant, he added: "Democrat immigration policies are destroying innocent lives and spilling very innocent blood. We believe that any party that puts criminal aliens before American citizens should be out of office, not into office."

Trump also posted a video on Twitter this week in which he used Tibbetts' death to attack Democrats over immigration policy.

"Mollie Tibbetts, an incredible young woman, is now permanently separated from her family," he said. "A person came in from Mexico, illegally, and killed her. We need the wall. We need our immigration laws changed. We need our border laws changed, we need Republicans to do it because the Democrats aren't going to do it."

Over the past few days, even as some members of Tibbetts' family have requested her death not be politicized, some Republicans have followed Trump's lead and used her death as a campaign season cudgel.

Particularly in Iowa, where the homicide occurred, the issue has been used to attack Democrats.

On Wednesday night, Iowa political blogger Laura Belin received and recorded a call from a firm called RTB Research that included a "question" about Cindy Axne, the Democrat challenging Republican Rep. David Young in the state's Third Congressional District.

Asked if certain statements would make her more or less likely to support Axne, the caller said:

"Recently, a University of Iowa student named Mollie Tibbetts was murdered by an immigrant in the country illegally. But Cindy Axne wants to join extreme liberals to abolish ICE, an immigration agency responsible for enforcing our borders and tracking down criminals who are in the US illegally."

In a brief interview with CNN, Axne called efforts to politicize the death "unconscionable to me" and said that while she believes the US immigration system is "broken" and in need of legislative repair, "abolishing ICE is absolutely not the solution."

"I called on Congressman Young to shut this down," she said of the poll, "and whether it was him or one of his allies, I think out of respect for Mollie's grieving family that he needs to make sure that this is taken out of the field as soon as possible."

"Our campaign has nothing to do with this poll and we have no knowledge of who may be behind it," spokesman Cole Staudt told CNN earlier Friday. Young, he added, was on the record saying "he didn't want to politicize this tragic event."

Iowa Republicans, from Gov. Kim Reynolds, who is also on the ballot this fall, to Sens. Chuck Grassley and Joni Ernst have made clear connections between Tibbetts' death and US immigration policy.

"As Iowans, we are heartbroken, and we are angry," Reynolds tweeted on Tuesday, soon after Rivera's arrest. "We are angry that a broken immigration system allowed a predator like this to live in our community, and we will do all we can bring justice to Mollie's killer."

In a joint statement , Grassley and Ernst echoed Reynolds' remarks and said, "Too many Iowans have been lost at the hands of criminals who broke our immigration laws. We cannot allow these tragedies to continue."

Ernst doubled down in a Thursday tweet linking to an interview she had done with Breitbart, a far-right website that regularly backs Trump, in which the host called the killing an "execution" and called out Massachusetts Sen. Elizabeth Warren for pivoting, during an interview on CNN's "New Day," from Tibbetts' death to criticism of the Trump administration's zero-tolerance border policy and the resulting family separation crisis.

"The families who are separated at the border will come together again," Ernst wrote. "Mollie will never be with her family again."

Fred Hubbell, the Democrat running to unseat Reynolds this fall, criticized state Republicans over their response on Thursday.

"This is really unfortunate that politicians all of a sudden are using this to politicize the event," he told KIMT during a visit to Mason City. "Let the family have time to grieve and deal with their loss. Take some time and give them some space."

Tibbetts' death has also become a talking point for some Republicans outside the state — and not just for the purpose of attacking Democrats.

Kelli Ward, a GOP Senate candidate in Arizona, used the killing to target fellow Republicans over their border policy positions.

"The lack of leadership & courage by open border senators like @JeffFlake, @SenJohnMcCain, & #amnesty advocate Martha McSally contribute to these senseless deaths," she tweeted on Tuesday night. "We need true leadership in the Senate to #BuildTheWall & secure our borders!"

McSally is the frontrunner in next week's primary.

On Thursday, the North Dakota GOP emailed out an editorial from the Grand Forks Herald that argued "Tibbetts might be alive today with better immigration laws."

In teeing up the piece, communications director Jake Wilkins called on Democratic Sen. Heidi Heitkamp, who is facing a challenge from GOP Rep. Kevin Cramer in November, to "talk with the families and victims terrorized by criminal illegal immigrants before attempting to dismiss this issue as just a Republican scare tactic."

Republicans have attacked Heitkamp, whose seat in a state Trump won by more than 35 percentage points in 2016 is among the season's most coveted, for voting against measures to withhold some federal money from "sanctuary cities."