Of the 10 candidates vying for five of the open seats in Brooklyn Civil Court in the Sept. 12 Democratic primary, five are running as part of an insurgent slate that seeks to shake up a system that they say is under the thumb of the borough’s Democratic establishment.

The slate is led by John O’Hara, a Brooklyn attorney who made headlines when he became the first person to be convicted of illegal voting since the 19th century, a charge that was later cleared after he was reinstated to the bar.