A key part of the problem, strategists say, is that the focus of the effort has been stopping the front-runner instead of promoting an alternative candidate. The movement never truly coalesced around Cruz, and the senator’s endorsements from reluctant Republican colleagues underscored the difficulty his campaign has in engendering excitement for him. Meanwhile, John Kasich now feels emboldened by the notion that Cruz can no longer win the nomination outright. But he and Cruz will be fighting over similar turf in a way that might benefit Trump.

“There’s been this ‘We’ve got to stop Trump,’ but not an equal amount of enthusiasm for ‘Let’s get behind Cruz to do that,’” says John Brabender, a GOP strategist and former adviser to Rick Santorum’s campaign.

“What’s happening is there’s already a transition to more of an inevitability with Donald Trump — more than there is an excitement to stop him,” he says. “And the sort of environment, that phenomenon is keeping the anti-Trump crowd from growing in size and volume.”