I don't see the anti-Trump tenor subsiding. I think it will get more intense, regardless. The point isn't necessarily to deny him success in upcoming primary elections, but rather to prepare the battlefield and justify handing the nomination to somebody else. If the nomination goes to Trump, then the relentless opposition will be used to justify the party working against its nominee in the general.
Sarah Palin had the line of the weekend in Wisconsin while Trump is talking about building a Wall, Ted Cruz and Glen Beck are handing out Soccer balls and Teddy bears to illegals at the border.
Ted backed 1.7 Million illegals legislation in 2013.