Texas again leads the nation in both percentage and number of uninsured, with both rising in 2018 to erase steady progress from previous years, according to new U.S. Census Bureau numbers released on Tuesday.

More than 5 million in the state lacked health insurance coverage last year, translating to 17.7 percent of the state's population. Although up only slightly from the 17.3 percent in 2017, it is seen as significant as the trajectory is moving in the opposite direction from historic gains of a few years ago.

In 2016, while still the highest in the nation, the Texas rate of uninsured had dropped to 16 percent -- a decrease advocates said was a direct result of the Affordable Care Act, which sought to bring nearly universal health coverage to the nation.

But with the change of administrations in 2017, the decline in uninsured in Texas and elsewhere stalled and then began to creep upward.

Nationally, the number of people who lacked health coverage in 2018 grew by nearly 2 million from the previous year, according to the new census figures. That marks the first increase since the health care law was fully in effect.

What is striking in Texas is not just the number of uninsured but the wide gap -- nearly double -- between its number and those of the next two highest states. In Texas just over 5 million are without coverage compared to about 2.8 million in California and 2.7 million in Florida.

The 17.7 uninsured rate also is significantly higher than the 14.2 percent and 13.7 percent rates in Oklahoma and Georgia, respectively, which round out the top three states with the highest rates of uninsured.

The number of uninsured children also grew by more than 400,000 nationally last year, the census report showed. While state-specific figures were not immediately available, broadly the biggest increase in children lacking coverage was in Southern states.

And while those covered by their parent's insurance remained about the same, there was a 1.3 percent drop in the number of poor children who receive coverage through public plans such as Medicaid and the Children's Health Insurance Program, or CHIP.

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"These are dangerous trends. We have worked really hard for a number of years to increase to the number and percentage of Texans who are covered by health insurance," said Elena Marks, CEO of Houston's Episcopal Health Foundation.

The rise in the uninsured rate was not unexpected. Many health policy experts had been predicting it for months especially as the health care law known as Obamacare continues to be under siege by critics. But it is noteworthy as it comes as the economy has strengthened and the overall poverty rate in Texas and across the nation declined.