Pella, Iowa (CNN) At a Wednesday Iowa rally, Jeb Bush addressed recent controversy over comments he made in his 1995 book that out-of-wedlock births were increasing because single mothers and fathers no longer faced public shaming.

Asked by an attendee why he would be in favor of shaming single mothers, Bush said, "I'm not in favor of shaming women. What I'm in favor of is shaming men who abandon their children."

"Women who bring up children by themselves do it heroically, they do it against all odds," Bush said. "Men who don't feel responsible for being part of their child's life create real strains on that family."

Bush went on to tout his record reforming child support laws and empowering families as Florida governor.

The presidential candidate first made his case in his 1995 book "Profiles in Character" -- which was published before he won the Florida governor's office -- in a chapter titled "The Restoration of Shame."

In an excerpt first cited by The Huffington Post last week, Bush wrote:

"One of the reasons more young women are giving birth out of wedlock and more young men are walking away from their paternal obligations is that there is no longer a stigma attached to this behavior, no reason to feel shame. Many of these young women and young men look around and see their friends engaged in the same irresponsible conduct. Their parents and neighbors have become ineffective at attaching some sense of ridicule to this behavior. There was a time when neighbors and communities would frown on out-of-wedlock births and when public condemnation was enough of a stimulus for one to be careful."

Wednesday's question signals that Iowan voters are taking note, and in an increasingly competitive primary, Bush faces an uphill battle in the early caucus state.

The remarks came at Bush's first major Iowa rally since declaring his candidacy. He spoke to hundreds at Molengracht Plaza in Pella, a Dutch-inspired town complete with windmills, authentic pastry shops, and an annual tulip festival.

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Bush also weighed in on the pending Obamacare ruling in Pella. Asked whether federal exchanges are legal, Bush said, "If you read the law, it doesn't appear like they are."

The Supreme Court could decide as soon as Thursday against the Obama administration over subsidies that help cover health insurance costs at the heart of Obamacare.

If the court rules federal exchanges unconstitutional, Bush said it would provide an "opportunity" to Republicans to repeal Obamacare and come up with an alternative.

"We (Republicans) also ought to be for replacing it with something that costs less, that adheres to our values, that provides portability, that eliminates the employer mandate, the employee mandate, all of this mind-numbing subsidies that are totally wacky, shifts power back to states," Bush said.

The former governor said health care plans are not one-size-fits-all and should be tailored on a state-by-state basis.

"Heavily regulated, mandated health care from Washington, D.C., isn't the fix. It's a disaster," he said.