I’m pretty sure there are still some deep pockets remaining. Perhaps they are waiting to see who emerges in the end. It look promising for Trump, but the primary isnt over. Still, it seem puzzling that the opposition to Trump isn’t fighting.
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I don't see a cease fire. I still see them fighting - just failing.
It could be they are in the process of firing their media marketing people and hiring new attackers. That takes time. Contracts negotiated. Budgets set. New strategies to be worked out for attack campaigns. Maybe it's too late? I can see an anti-Trump PAC going to people who do this for a living and I can see those people saying - "we can take your money but what we do may not work at this stage of the campaign".