Since the turn of the 20th century, Republicans have never known a majority in the North Carolina Senate.

Many knowledgeable political observers believe the size and makeup of Senate districts actually provide better advantage for the GOP than those in the House. Nonetheless, Democrats have held a firm grip on the Senate during a 12-year period in which Republicans and Democrats have maintained relative parity in the House.

Two reasons for the GOP's lack of success:

-- Pro-business, fiscally conservative Democrats like David Hoyle in Gaston County and Walter Dalton in Rutherford County have kept seats that could easily swing Republican once the longtime incumbents leave office.

-- The Senate Democrats' campaign operation is a well-oiled machine. Since Senate Leader Marc Basnight has been at the head of the chamber, Democrats have effectively targeted districts in which they have a shot and cut their losses in those where they have none.

Given their 29-21 majority going into this fall's election, the Democrats' reign in the Senate looks to continue.

Contested races will take place in 28 of the 50 districts. But those likely to be truly competitive could nearly be counted on one hand.

Republicans will have the most opportunity for gain because Democrats control seats most likely to change hands.

The District 2 race between Democrat Pete Bland and Republican Jean Preston may represent the GOP's best chance to pick up a seat. The district includes coastal Carteret, Craven and Pamlico counties, a region which has seen strong growth in moderate Republican and independent voters over the past 15 years.

Bland, a longtime sheriff and county commissioner in Craven County, was appointed to the seat earlier this year. Preston is a retired teacher who has served in the House for 14 years.

Republicans also look for potential gains against two one-term, Democratic incumbents -- Julia Boseman in District 9 in New Hanover County and John Snow in District 50 in the far western mountains.

Boseman, a former New Hanover County commissioner, is the first openly gay legislator in the state's history, but sponsored bills -- such as one targeting violent video games -- which hardly paint her as a liberal. Her opponent, Al Roseman, is a dentist and member of the University of North Carolina Board of Governors.

Snow, a retired District Court judge, faces Republican Ken McKim, a Texas native who co-owns a construction company.

Dalton, in District 46, may also face his toughest challenge in a while, taking on an aggressive campaigner in Wes Westmoreland, the owner of a printing company.

Democrats' best opportunity to add a seat will likely come in District 47, another large mountain district.

In a rematch of a 2004 contest, one-term Republican Sen. Keith Presnell takes on former Democratic Sen. Joe Sam Queen.

Other senators -- Democrats John Kerr and Martin Nesbitt, and Republicans Neal Hunt, Harris Blake and Hugh Webster -- will also be nervous come Election Day. But a loss by any of the five would be considered a significant upset.

Scott Mooneyham writes for Capitol Press Association. Contact him at smooneyh@ncinsider.com