It was was actually Pence's idea. Pence was visiting NASA and Bridenstine mentioned to Pence that getting into moon by 2024 was possible. Pence just added the new policy goal into his speech on the spot and it became the official policy of the Government.

https://www.whitehouse.gov/briefings-statements/remarks-vice...

>In Space Policy Directive-1, the President directed NASA to create a lunar exploration plan. But as of today, more than 15 months later, we still don’t have a plan in place. But Administrator Bridenstine told me, five minutes ago, we now have a plan to return to the moon. (Applause.)

... little later

>And I’m here, on the President’s behalf, to tell the men and women of the Marshall Space Flight Center and the American people that, at the direction of the President of the United States, it is the stated policy of this administration and the United States of America to return American astronauts to the Moon within the next five years. (Applause.)

Of course, this does not mean anything. WH is not committing any work towards that goal and probably don't know how. They just said it, requested money and left it there hanging. NASA has funding for Moon mission in 2028. The extra money to get there faster is nowhere to find.

It's also the year he would become a lame duck if he gets reelected. Very low risk thing pay lip service to for him.

I doubt it's his idea though, nor of any of his cabinet. Just a convenient thing for him to latch on to politically.

I believe your response is emblematic of the budgetary responses from the democratically controlled HOR: To hell with what the people want and need, "If Trump wants it, it must be bad".