The visit also cast a bright light on staunch opposition to the law in Republican-leaning Texas, which has the highest rate of uninsured Americans — more than 23 percent. GOP Gov. Rick Perry has refused to take advantage of a provision in the law to expand Medicaid to cover more of the working poor.
Obama said Texas' neighbors had looked at the Medicaid expansion, which is fully funded by the federal government for the first few years, as a no-brainer.
"I know that sometimes this task is especially challenging here in the great Lone Star State," Obama said to laughter. "But I think all of you understand that there's no state that actually needs this more than Texas."
Perry shot back, accusing Obama in a statement of trying to "salvage his ill-conceived and unpopular program from a Titanic fate."
"Texans aren't the reason Obamacare is crumbling," Perry said. "Obamacare is the reason Obamacare is crumbling."
Texas also is among the 36 states not providing their own insurance marketplaces, which means residents there must sign up through the federal website that stumbled badly upon its launch Oct. 1.
Before leaving Dallas, Obama also planned to attend two fundraisers for the Democratic Senatorial Campaign Committee.
Back in Washington, Health and Human Services Secretary Kathleen Sebelius faced heated questioning from senators, some of whom challenged her honesty and demanded she resign. Focusing on progress made, Sebelius said the web portal now is handling large volumes of material with fewer errors even as she acknowledged "we're not where we need to be."
Obama has been aggressively promoting the law in the face of numerous setbacks. In addition to the problem-plagued enrollment launch, insurers have been sending some of their customers termination notices because their policies don't meet federal requirements.
The notices have put Obama and White House officials on the defensive as they attempt to explain Obama's early vow that under the new law, people who like their existing coverage would be allowed to keep it.