The editorial then goes through the list of other Republicans vying for the nomination, none of whom has been able to launch a viable statewide campaign, and acknowledges Mandel's establishment support and fundraising prowess, calling him driven and intelligent.
"Mandel will win the nomination, as he should, despite his flaws," the paper wrote.
Republicans pointed out that Brown's wife, journalist Connie Schultz, worked as a columnist for the Plain Dealer, and said it wasn't surprising the paper would criticize Brown's opponent.
Recent polls show Brown with a lead of between 4 points and 13 points in a general-election matchup against Mandel.
- This post was updated at 2:28 p.m.