It was just two months ago that Walker made his first trip into Iowa as declared official presidential candidate, amid soaring poll numbers and expectations for him in the state.

On his latest Iowa swing, the fallen Iowa front-runner showed an increased willingness to draw contrasts with other candidates, including Trump, retired neurosurgeon Ben Carson and former Hewlett-Packard CEO Carly Fiorina.

“You wouldn’t hire me to build condos for you in New York City, or to be a neurosurgeon, or to run HP, because that’s not where my skill sets are,” he said in Vinton. “But if you want someone who has got a proven track record of taking on the Washington-based special interests and winning, if that’s what you want—somebody who can shake things up in Washington—then I’m tested unlike anybody else in this race.”

Speaking to reporters in Amana, Walker said he’s convinced the donors in his database of 350,000 supporters from all 50 states will stick with him, in part on the strength of that network.