What did Donald Trump do today?

He forgot what his trade policy was in the middle of the trade war he started.

Trump told Republicans at a White House meeting today that he was considering rejoining the Trans-Pacific Partnership, the multi-nation trade pact better known as TPP. This was confirmed by multiple Republican lawmakers, including Sen. Ben Sasse (R-NE) and Sen. Pat Roberts (R-KS). 

Trump reportedly told his new economic advisor Larry Kudlow to "get it done." Withdrawing from the TPP was something Trump "got done" on his third day in office. At the time, he called abandoning the TPP "a great thing for the American worker, what we just did."

On the campaign trail, Trump compared the TPP to rape, saying, "The Trans-Pacific Partnership is another disaster done and pushed by special interests who want to rape our country, just a continuing rape of our country. That’s what it is, too. It’s a harsh word: It’s a rape of our country."

In tweets, Trump also called the Obama administration "incompetent" for taking part in it, said that Republicans too were "stupid" for supporting it, and that it was a "bad deal" because it was a "job killer."

There was no obvious explanation for Trump's sudden and radical change in policy, except that on matter ranging from health care to immigration, he often seems to forget what his stated policies are. He's also prone to taking the position urged by the last person to talk to him before a decision needs to be made, which may have been how Republicans from agriculture-heavy states threatened by Trump's trade war talked him into this.

The TPP went into effect without the United States under a slightly different name, and there is no reason to believe the United States will have any advantage in negotiating entry now--especially since Trump is still threatening punitive tariffs against many of its members.

So what?

• It's bad if a president's positions on major policy issues change rapidly and unpredictably.

• It's still bad if the president can be easily manipulated, even if results those manipulations are for the best.

• This kind of thing doesn't happen to presidents who understand the issues they're making decisions about in the first place.