He's in Washington now and this allegedly dealmaking power is nonexistent.
Republicans and Democrats in the Senate yesterday cobbled together an agreement to reopen the federal government for a few weeks. And Donald Trump was entirely absent from any of that dealmaking. He was off in the White House watching daytime television.
As Josh Barro wrote at Business Insider yesterday (link here): "The President’s shifting positions are a problem that has contributed to the shutdown. But there’s another, related issue: Members of Congress in both parties believe the President is a weak negotiator. This discourages them from compromising, even among themselves, because they believe they’ll eventually be able to roll Trump closer to their own position. Why cut a deal now when you believe you’ll eventually be able to get Trump alone in a room and he’ll agree to give you more?"
Over at The Washington Post, Jennifer Rubin wrote (link here): "Both sides know better than to negotiate with ... Trump. Removing him from the equation ... should make a deal possible. The great dealmaker has been sent out to pasture... Trump was exposed as a non-player, a hazard to dealmaking. That’s quite a blow to his brand."
At this point, the only people left believing Trump is some fabulous dealmaker are the President himself and his die-hard supporters. Everyone else has seen the emperor's new clothes for what they are.