GOP strategist Bob Haus, who ran Rick Perry’s two Iowa campaigns and is a frequent Trump critic, is among the plugged-in Republicans here who senses that Cruz is heading in the wrong direction at the worst possible time.

“I think Cruz peaked too early, became the target, and has sustained over a month of concerted fire from all quarters,” Haus said. “It’s taken its toll.”…

With public interest in this year’s Republican race at unprecedented levels, even Cruz’s top backers here are predicting the 2016 caucuses will exceed the numbers of 2012.

Bob Vander Plaats, an influential Iowa Christian conservative leader who has endorsed Cruz and sparred with Trump publicly, predicted that turnout on Monday would be somewhere in the 135,000 to 150,000 range.

“We’re in uncharted territory,” Vander Plaats said.