TAMPA — Democrats all but clinched a historic victory Tuesday as two political novices looked likely to defeat better-funded GOP opponents, turning Hillsborough County's most powerful political body blue for the first time since 2004.

The most-watched races were for two countywide seats where Democrats Mariella Smith was on her way to oust Republican incumbent Victor Crist in District 5 and Kimberly Overman looked nearly certain to best Todd Marks in District 7.

"Well, it's about time," Overman said Tuesday night. "Clearly, we needed some balance on the board. It's a little overwhelming and wonderful."

According to unofficial results, with 354 of 390 precincts reporting, Overman was beating Marks by a 53-46 margin while Smith was defeating Crist by a similar spread, 52-45.

Smith and Overman had an edge in political demography. Democrats have 65,443 more registered voters in Hillsborough than Republicans. And a heavy turnout appeared to have furthered their cause.

County Commission candidates struggled to grab voters' attention in an election dominated by national and state races, a challenge made even more difficult in a county in which two separate tax proposals dominated politics in Hillsborough.

In District 5, Crist, 61, was seeking his third term in office, switching from District 2 to avoid term limits. He raised $100,000 more than Smith.

In her first run at office, Smith, 64 raised $172,000. The owner of a graphic design firm, she campaigned on improved transportation, more affordable housing and making developers pay more for new roads and schools.

"This lets us come in with a mandate to do the things we've been talking about for a year," Smith said.

Crist said he was looking forward to retirement and spending more time with his 6-year-old daughter.

"I don't see this as a blue wave," he said. "I see this as a sign from independents and non-partisan voters that they're not happy with the local Republican Party."

Independent candidate Joe Kotvas, 75, finished far behind with a relative handful of votes.

In District 7, Overman, the 60-year-old owner of a financial planning firm, was out-spent by Marks, 48, an attorney from Westchase — $285,771 to $155,509 — enabling Marks' campaign to flood voters' mailboxes with negative mailers linking Overman to the liberal wing of county politics.

Also in the race was Kim "KLARC" O'Connor, who finished a distant third with about 2 percent.

In the other two County Commission races, incumbent Republicans Ken Hagan in District 2, which covers northern and east-central Hillsborough County, and Stacy White in District 4, which encompasses much of the eastern part of the county, appeared ready to win, but Hagan's race was closer than expected.

Hagan, 51, who has served on the commission since 2002, ran a quiet campaign. A leader of the effort to bring the Tampa Bay Rays to Ybor City, Hagan was defeating political novice Angela Birdsong, 58, by a 52-48 margin with 98 out of 106 precincts reporting. The close result came despite Hagan's $555,349 campaign war chest — more than 15 times the $33,846 Birdsong raised.

White, 46, elected to the commission in 2014 after a Hillsborough School Board term, was viewed as a strong favorite to retain the mostly rural and suburban seat where registered Republicans outnumber Democrats by more than 11,000.

White was defeating first-time candidate Andrew Davis, 36, by a comfortable 58-42 margin with 87 of 99 precincts reporting.

County commissioners serve a four-year term and are paid $99,997.