From 7 a.m. to 8 p.m. today, voters across Pennsylvania will be going to the polls to produce a new justice of the state Supreme Court, a new prosecutor in Bucks County, and the first new Philadelphia district attorney in 19 years.

Scores of county, municipal, and school board posts are also in contention.

Topping the ballot statewide, Democrat Jack Panella, 54, and Republican Joan Orie Melvin, 53, are vying for one open seat on Pennsylvania's highest court.

In Philadelphia, Democrat Seth Williams, 42, and Republican Michael Untermeyer, 58, are competing to succeed District Attorney Lynne M. Abraham, who is stepping down after nearly two decades in the job.

In Bucks County, Republican David W. Heckler, 62, is battling Democrat Chris Asplen, 45, to replace District Attorney Michelle Henry, who was appointed two years ago but decided not to seek a full four-year term.

If Asplen wins, he will be the first Democrat elected to the office since 1891.

So much for the high-profile contests.

Other rivalries typically pit incumbents against challengers, with outcomes that could swing erratically because voter turnout is expected to be exceptionally low. Election officials in Philadelphia and some suburbs in Southeastern Pennsylvania predict that fewer than one in five registered voters will cast a ballot.

The closest contest inside the city is the face-off between City Controller Alan Butkovitz, the incumbent Democrat, and Republican challenger Al Schmidt.

Observers say Butkovitz, 57, a former state representative, harbors mayoral aspirations but first needs to win reelection to the office he has held since 2006. Schmidt, 38, is a former senior policy analyst for the U.S. Government Accountability Office making his first run for elective office.

In addition to choosing a new justice of the state Supreme Court, voters will elect judges to the middle-rung appellate courts - four to Superior Court, two to Commonwealth Court - and dozens to county-level courts.

None of the Philadelphia judgeships - seven for Common Pleas Court, four for Municipal Court - is contested.

Seventeen sitting judges - nine from Common Pleas Court, six from Municipal Court, and two from Traffic Court - also are on the ballot seeking retention. Voters are asked whether a judge should be allowed to serve another term, ranging from six to 10 years depending on the judicial position.

At a news conference yesterday, Philadelphia First Assistant District Attorney Arnold Gordon said his office would have several mobile units available to respond to voter complaints. Each unit is staffed with an assistant district attorney and a county detective.

Anyone interfering with another person's right to vote may be prosecuted, Gordon said. His office will field complaint calls at 215-686-9641.

The independent election watchdog group the Committee of Seventy also will be available to answer voters' questions at 215-557-3600.

In addition, U.S. Department of Justice observers will be in Philadelphia to monitor compliance with the Voting Rights Act of 1965, which prohibits racial discrimination and other abuses.

Get the latest election results from the New Jersey governor's race, as well as other election news from around the region, at www.philly.com

Get the latest election results from the New Jersey governor's race, as well as other election news from around the region, at www.philly.com

Contact staff writer Michael Matza at 215-854-2541 or mmatza@phillynews.com.

Contributing to this article were staff writers Joseph A. Slobodzian, Larry King, and Tom Infield.