Trump critic George Conway, Kellyanne Conway's husband, donates $5,600 to Trump GOP challenger Joe Walsh

George Conway, an outspoken critic of President Donald Trump and husband of presidential counselor Kellyanne Conway, has donated the maximum amount allowed to the presidential campaign of Republican challenger Joe Walsh.

Conway gave $5,600 to the former congressman's campaign on Aug. 30, just days after he announced his candidacy, according to a new campaign finance report filed on Tuesday.

A conservative lawyer based in Washington, D.C., Conway has been one of the biggest and consistent critics of Trump within the Republican Party.

Earlier this month, Conway penned a fierce op-ed in The Atlantic, titled "Unfit for Office," once again calling into question Trump's mental fitness to hold office. And just this Monday, Conway went on Twitter to call him "incompetent and ignorant" and took aim at Republicans for not mentioning Trump's name while criticizing his policies.

Kellyanne Conway has served as one of Trump's closest aides since his presidential campaign in 2016, and has served as the president's counselor in the White House since his victory.

Walsh, too, has aggressively hammered the president since announcing his long-shot candidacy for the GOP nomination in August, arguing that Trump is further driving a wedge between the Republican Party and the coalitions of voters needed to secure the White House.

"The problem is an unfit president in the White House who took a divided country and is dividing that," Walsh said recently at an unsanctioned GOP primary debate last month.

"The Republican Party brand sucks, and it sucks because of him," he said. "Young people can't stand the party, women can't stand the party, black people who live in the suburbs can't stand it."

In the latest campaign finance disclosure, Walsh reported raising about $129,000 from his supporters between August and the end of September, compared to a massive $125 million haul the Trump campaign has brought in along with the Republican National Committee between July and September.

Despite the massive uphill climb ahead of him, Walsh remains adamant that conservatives should get behind an alternative Republican in 2020.

"I'm running because he's unfit; somebody needs to step up and there needs to be an alternative. The country is sick of this guy's tantrum -- he's a child," said Walsh, who was elected to the House in the 2010 Tea Party wave, but only served one term before becoming a conservative talk radio host.

Walsh, along with the other Republican primary challengers to Trump, are contending with other forces beyond the president, mainly the Republican National Committee giving "undivided support" to the president - even passing an unprecedented loyalty pledge earlier this year before he's the party's official nominee.

As part of that pledge, several state parties have moved forward with forgoing their nominating contests in 2020, including South Carolina, Nevada, Kansas and Arizona. It has also led to 37 states and territories tightening the rules for choosing delegates to the Republican National Convention, an effort quietly helmed by Trump campaign officials.