Republicans.

«In the November elections, Republicans gained seats in the House and came one seat shy of gaining a supermajority in that chamber. So Democrats hold enough votes in the House to protect Cooper’s veto. But with the new rules in place, Democrats fear Republicans will call surprise votes to override Cooper if a couple of their members are absent.»

https://www.wral.com/nc-house-republicans-scrap-rule-on-veto-override-votes/20667372/