Donald Trump has ordered Homeland Security to launch a nationwide voter fraud crackdown targeting key swing states as Republicans brace for a brutal midterm fight.

Beginning Tuesday, Homeland Security Investigations, ICE's investigative arm, will launch a 'coordinated criminal voter fraud surge initiative to pursue investigative leads, conduct field interviews, and support timely prosecutorial review,' CNN reports.

The operation, aimed at substantiating Trump's claims that widespread voter fraud - including by illegal immigrants - has marred recent elections, will authorize agents in nine states to pursue investigative leads through mid-October.

The initial sweep is expected to cover Washington, Wisconsin, Missouri, Georgia, California, Pennsylvania, Nevada, New York and Connecticut.

Agents are being directed to take visible investigative steps just as the midterm election season gets underway, according to CNN. 

The Justice Department has traditionally discouraged such policy to prevent law enforcement from influencing an ongoing election.

Homeland Security Secretary Markwayne Mullin, who replaced Kristi Noem after Trump fired her in March, has pushed to turn the department into a powerful new force in the president's effort to root out alleged election fraud.

DHS has demanded that states hand over their voter rolls for audits, while Mullin has repeatedly threatened to withhold grant funding from those that refuse to adopt the administration's election reforms.

'DHS is laser focused on prosecuting and removing aliens who vote and preventing the dilution of the votes of US citizens,' a Homeland Security spokesperson told the Daily Mail. 

'Our message to aliens who vote in American elections is clear: we will find you, arrest you, and you will face the consequences — including criminal charges and deportation.'

HSI, the agency leading the voter fraud investigation surge, has typically been used to tackle major crimes such as human trafficking, drug smuggling, and child exploitation. 

Mullin has already assigned an unprecedented number of investigators to examine the voting histories of suspected noncitizens who may have illegally registered or cast ballots in past elections.

HSI agents were previously ordered to coordinate with US Citizenship and Immigration Services on removal proceedings involving noncitizens suspected of committing or being linked to voter fraud.

Despite the sweeping effort, the Trump administration has so far referred relatively few voter fraud cases for prosecution.

Earlier this summer, Mullin announced that a DHS audit had uncovered more than 250,000 noncitizens on public voter rolls in California, Pennsylvania, New Jersey and Nevada.

'One thing that I love about numbers, and I love about facts, is they don't lie,' Mullin said to reporters at the time.

The latest crackdown scheduled to start Tuesday comes as Republicans in Congress face the possibility of losing their majorities in the House and Senate.