With a looming deadline days away, Gov. Mark Dayton urged Minnesotans to sign up for health insurance through MNSure, saying vast improvements have been made to the state's trouble-plagued health insurance exchange and that it'll take time before its success can truly be gauged.

Dayton declared Friday MNSure Enrollment Day in the final push to get Minnesotans signed up by March 31. More than 152,000 people have signed up through the exchange, exceeding a revised goal set in October to help 135,000 Minnesotans acquire coverage. The total is well below the original projection of 164,000 to 270,000 enrollees.

Interim CEO Scott Leitz said extra staff will be on hand this weekend to help with enrollment, but more people rushing to sign up could result in longer hold times. People who encounter difficulties will be issued hold forms to ensure they were waiting in line before the deadline--similar to being in line when the polls close, he said.

Leitz said about 20 percent of MNSure enrollees are young adults, the demographic vital for subsidizing older Minnesotans more likely to need healthcare. He said MNSure didn't set a specific target for how many young people they need, but that "a strong, broad mix of people" is necessary, which will require as many younger Minnesotans as possible.

Currently, about 42,000 Minnesotans are enrolled through qualified health plans, while 110,000 are through Medicare and Medicaid.

Leitz was summoned Thursday to testify before Congress about MNSure's troubled rollout. However, Dayton defended the improvements made to the program, saying success cannot be measured after this enrollment period. He also blasted GOP criticism of the program without having offered alternatives.

"Success can't be measured after this enrollment period. I think after the next (fall enrollment) we'll have a better idea of the progression and maybe three years before people are aware of this program and the obligations," he said. "Changing people's behavior…takes some time. This is not going to happen overnight, it's not intended to happen overnight."

But GOP critics contended the number of Minnesotans who lost their health plans outnumbered those who were satisfied, with no potential solutions in sight.

"We haven't heard a single proposal from the governor or the legislature to fix the fundamental structural flaws in MNSure," said Sen. Michelle Benson, R-Ham Lake. "I would not call today a day to celebrate the successes of MNSure."