The centrist group Main Street Advocacy on Tuesday lashed out at the conservative Club for Growth for targeting Republican incumbents in primaries, with its leader calling the Club "a cancer" on the GOP.

"The Club for Growth is a cancer on the Republican Party that prides itself on supporting rigid, divisive and obstructionist candidates," said former congressman Steven LaTourette (R-Ohio). "They are certainly entitled to support any candidate they want for any reason they want, but it would be nice if they told the voters the truth about their organization and if they won't tell voters the truth, we will."