Democratic challenger Susan Evans, who unseated Wake County school board Chairman Ron Margiotta on Tuesday, was supported by a stream of mailers into homes in District 8, the southwestern part of the county.

The mailers attacked Margiotta, a Republican, as a tea party extremist. A wide-ranging effort also included phone calls, polling and other campaigning, including poll workers.

Unofficial tallies show that Evans' biggest support came from areas with more Democrats along N.C. 55 in Apex and Holly Springs, and from voters who cast their ballots early.

Here's a breakdown of the voting.

1 The district: District 8 covers a wedge generally southwest of where U.S. 64 and U.S. 1 meet in Cary. It stretches from Durham County in the north to Fuquay-Varina in the south. The district leans Republican, with 36.5 percent registered Republicans to 30.8 percent registered Democrats. Unaffiliated voters make up 32.3 percent of those registered.

2 The history: Margiotta ran unopposed in 2007. In 2003, he won his seat with 56 percent of the vote in a three-way race. That year's turnout was 7,906 voters, well below Tuesday's turnout of 13,628.

3 Tuesday's margin: Evans beat Margiotta by 585 votes out of the 13,628 ballots cast. Evans received 52 percent of the vote to Margiotta's 47.8 percent - a comfortable margin, but the closest of the five school board races held Tuesday.

4 Early voting crucial: Evans received a huge advantage from people who voted in "one stop" balloting prior to Election Day, getting 618 votes to Margiotta's 240. That difference of 378 votes in Evans' favor is a large part of the overall difference between the two candidates' votes. Absentee voters were split between the two (159 votes for Evans to Margiotta's 151).

5 Democrats for Evans: District 8 has 20 precincts. But only five of those precincts have more registered Democrats than Republicans. And those five districts were crucial for Evans - she won four of them by a combined margin of 336 votes.

6 Shallow Margiotta support: Evans also polled well in several precincts with substantial numbers of Republican voters. One of them is her home district, which she carried with 379 votes to Margiotta's 292. But another example is Precinct 18-05, in a fast-growing area east of Cary's Regency Park, that includes neighborhoods along Ten Ten Road. Forty percent of its registered voters are Republican. It was the precinct with the heaviest voting (8.5 percent of all ballots cast in the district), and Evans won it by 87 votes.