RALEIGH, N.C. -- Supporters of North Carolina's major political parties are picking their candidates for seats in the state legislature at a time of major turnover.

Primary elections being held Tuesday will narrow down the races for the 170 seats in North Carolina's General Assembly.

One big factor this year is the mid-decade redistricting ordered by federal judges who found Republican legislators illegally designed voting districts with racial bias in order to favor themselves.

That led to retirements that have left a dozen open seats this year. Two sets of GOP senators will be forced to run against colleagues after being placed in the same district.

Another anomaly this year is that nearly three dozen other Democratic or Republican incumbents are being challenged within their party.

Eight congressional incumbents are also trying to advance through Tuesday's primary elections. 

Sitting members of Congress seeking re-election include House Freedom Caucus Chairman Mark Meadows and Rep. Patrick McHenry, the chief deputy whip in the House. The most threatened GOP incumbents may be Reps. Robert Pittenger of Charlotte and Walter Jones of Farmville. 

A little over 4 percent of the state's 6.9 million registered voters cast ballots before Tuesday through early in-person or traditional absentee voting.

Some registrants had no primaries in which to vote because there are no statewide races on Tuesday's ballot. 

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