Mark this one as an inexplicable development in state politics. Four Republican candidates are competing in a primary in N.C. House District 50, currently represented by Democrat Bill Faison, who opted to run for governor rather than seek another term in the legislature.

Funny thing is, district 50 is heavily Democratic. It encompasses Durham and Orange counties — what Jesse Helms would have called “zoo territory.” Victory by a Republican in the general election is very unlikely. So that makes the high number of GOP candidates who want the nomination a bit puzzling.

The only other GOP primary in the House with four candidates is in district 109, which is heavily Republican.

In 2008, President Obama carried district 50 57-42 percent, Gov. Perdue 54-42 percent, and Sen. Hagan 58-40 percent. Voter registration favors Democrats two-to-one.

The only chink in the Democrats’ armor here is that the district is an open seat due to Faison’s retirement to run for governor, so there isn’t the power of incumbency.

The GOP candidates: Lewis Hannah, Rod Chaney, Thomas Samuel Wright, and Jason Chambers.