The filing deadline for candidates wishing to seek a major party nomination expired last month and several key contests in western Prince William County so far do not have opposition party challengers.

Overall, Democrats have struggled more than Republicans. As of this past weekend, Democrats had yet to field candidates for three Board of County Supervisors seats, three House of Delegates seats, the 28th state Senate district and sheriff.

Sheriff Glen Hill does face an independent challenge from Mike Messier, one of his 2007 primary opponents. Messier is running as a more conservative alternative to Hill.

For their part, Republicans are not contesting the candidacies of state Sen. Chuck Colgan (D-29th), Neabsco Supervisor John Jenkins (D) and Commonwealth's attorney Paul Ebert (D).

Colgan, the dean and president pro tempore of the General Assembly's upper chamber, is running unopposed in both the Democratic primary and general election for his Manassas-based seat.

His staying power played a major role in that, according to Prince William County Republican Committee chairman Lyle Beefelt.

"I think that's the biggest thing, that it's hard to get someone to roll the dice against someone that's so entrenched," he said.

Meanwhile, Brentsville District Supervisor Wally Covington (R) faces a tough primary challenge from Jeanine Lawson (R). However, the winner may be able to take the seat in a cakewalk come the fall as the Democrats, once again, have no announced candidate despite an easier district since some conservative precincts have been redrawn into Coles.

For the second consecutive cycle, the same thing also happened in Occoquan District, where Supervisor Mike May (R) is completing his first full-term in office since his 2007 special election victory.

According to Prince William County Democratic Committee chairman Bruce Roemmelt, the party may not have anyone run for either seat.

"I'm not going to have somebody that's just going to be a placeholder," said Roemmelt, who was actively talking to someone this weekend about challenging Supervisor Maureen Caddigan (R), whose district is now called Potomac instead of Dumfries.

Instead, he said he wants a candidate who will focus on retail politics and understands the election process.

"I don't put the fear of God into them," said Roemmelt, who lost two races to Del. Bob Marshall (R-13th) last decade. "I tell them what the realities are."

None of this is to suggest that the there will no be major party opposition in the fall. The committees can still appoint someone to run when party members officially select their nominees next month.

However, what this scenario suggests is that a combination of redistricting and the power of incumbency is weighing heavily on the minds of potential challengers.

In the General Assembly's lower chamber, Dels. Jackson Miller (R-50th) and Rich Anderson (R-51st) face no competition. This comes after Miller faced the same Democrat, Manassas Park resident Jeanette Rishell, three consecutive elections in a row.

Anderson upset former Del. Paul Nichols (D) during the Republicans' sweep in 2009. At the time, the 51st district could have been considered battleground territory as its voters near the Occoquan River traditionally are ticket-splitters.

After redistricting, the lines have been gerrymandered in a way that the district no longer runs up and down the river but instead extends the width of the county, creeping into much more reliably-safe Republican territory in western Prince William communities like Nokesville and Brentsville.

The same process also helped Del. Tim Hugo (R-40th) gain stronger Republican precincts as his Centreville-based district now extends through Manassas National Battlefield Park and in to Gainesville, Catharpin and Haymarket.

Like Miller and Anderson, the fourth-term delegate faces no opponent.

"The power of party and incumbency is a strong combination," said Beefelt.