Judging by reaction at the University of North Florida last week, Jacksonville-area young adults dig politics.

Whether they packed campus viewing parties, tweeted their thoughts or yelled in protest, they made a splash at the Republican presidential debate that drew 5.4 million viewers nationwide, according to CNN.

But a recently released study says network-induced excitement isn’t the best for popular democracy in the Sunshine State. Floridians ages 18 to 29 have the lowest level of civic engagement in the nation, according to the 2011 Florida Civic Health Index.

Researchers with the University of Florida, the University of Central Florida, the Florida Joint Center for Citizenship and the National Conference on Citizenship produced the report using census data.

Among the findings:

■ Fewer than half of Florida millennials are registered to vote, which mirrors the national average of 44 percent.

■ Only one in five voted in the 2010 midterm elections.

■ Florida young people rank 48th in the nation for participation in religious, school, neighborhood or sports and recreation groups.

Many 20-somethings say their generation is more engaged than it appears, because of social media. With smartphones, they can connect to family, friends and news sources instantly.

But that doesn’t push them to necessary action, according to Ann Henderson, director of Florida’s Bob Graham Center for Public Service.

“They participate in political blogs and think that is a form of engagement. But it’s rarely a discussion. It’s usually one-way,” said Henderson, whose organization worked on the Civic Health Index. “That is not the skill that democracy needs.”

Ali Brin, a UNF accounting junior, doesn’t see it that way. She can get behind a political candidate who supports what’s important to her: women’s equality, gay rights and funding for the arts.

Without social media, the 20-year-old said, she might not know as much as she does.

“We have Twitter so that we can follow any newspaper that we want. We have Facebook, where we can like any service we want, any organization,” Brin said. “We can find out information as quick as we can type it into our iPads.”

Ben Ruffner, a 27-year-old from Jacksonville who plans to vote in Tuesday’s Republican primary, is looking way into the future. His concern? What the baby boomers are doing to his retirement.

“The largest issue I’ve got is probably stealing from my generation and the generations that are to follow. Social Security is just being depleted,” Ruffner said. “I want a candidate who is going to step forward and who is going to set forth a balanced budget, who has a detailed plan on that.”

For some, politics isn’t that important.

UNF senior Katie Boyle voted in the 2008 presidential election, the first time she could exercise that right. That race was exciting, she said, because the country was on the verge of electing its first black president. And Barack Obama’s campaign used social media to reach young people like Boyle.

This time around, Boyle is less interested. In fact, politics was an irritant the day of the Republican debate. At least one of her professors canceled class because of expected parking problems — which can be bad on a normal school day.

“This time, I’m graduating. I have stuff to think about,” the 22-year-old said. “I don’t read the newspaper. I’m not informed at all.”

The Civic Health Index says college-educated millennials are more engaged than those with less education, as are wealthier households.

Race and ethnicity seem to be a decreasing factor, Henderson said, which could be Florida’s bright spot. As the country grows into one with no racial majority, Florida could become a national leader. But only if young people get involved.

“If we can figure it out in Florida,” Henderson said, “we would be able to pass along what the rest of the country will really need in 50 years.”