Quoting the 10th Amendment to the U.S. Constitution, Texas Gov. Rick Perry told a Davenport audience Tuesday that he is the best candidate to overhaul the federal government.

He also mounted a strong defense of his state's health care system when asked about its high rate of uninsured children.

Perry spent much of the day in the Quad-City area, campaigning with Louisiana Gov. Bobby Jindal at events in Maquoketa, Clinton and Davenport, as well as a stop along DeWitt's main downtown street.

On a statewide bus tour, Perry's route ran through eastern Iowa the same day his campaign released a new TV advertisement accusing rival Newt Gingrich of being the candidate of "K Street" and Mitt Romney of "Wall Street."

Of Romney, Perry said "he made millions buying companies and laying off workers."

In front of about 150 people at the Figge Art Museum, Perry said he would cut regulations, make lawmakers part-time legislators, and limit the federal government.

The governor also gave a spirited defense of his state's health-care system when a woman asked him why, with the economic growth in Texas, the state has so many children without coverage. More than 1.2 million Texas children are uninsured, the highest in the country, according to U.S. Census data.

"It's because Texas has chosen to have that type of health-care delivery," Perry said, using the occasion to compare his state's approach with that of Massachusetts, which passed a universal health-care plan when Romney was governor that contained a requirement that individuals buy health insurance.

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Romney has been criticized for the plan, and rivals have said it was a model for President Barack Obama's health-care law.

"This is a 10th Amendment issue for me," Perry said, and he rejected the idea that children don't have access to health care just because they don't have insurance. "We've chosen not to spend our money on insurance," he said.

Perry, who was criticized earlier this year for a policy giving in-state tuition to the children of illegal immigrants, said he would secure the country's southern border within a year of taking office. And he proposed a new Monroe Doctrine, complaining about Iran's ties to Venezuela.

The original 1823 doctrine warned European powers against seeking to colonize American continents. Perry warned such ties and a porous border represent a threat to the United States.