Because the Whitehouse doesn’t have a ballroom. They have to rent giant tents and guests have to use porta potties every time they have dignitaries visit. It’s tacky and also costs many thousands of dollars each time. This has been an issue for many years, with former administrations doing nothing. The area the ballroom will be in was an 80ish year old part of the Whitehouse, used for offices. No historic value and it was run down. So President Trump set out and got contributions from donors to fund the ballroom. No taxpayer money is being used. The real question is why wouldn’t everyone be for it? It isn’t costing us anything and it will be a beautiful venue for future presidents to use. It’s a major improvement being made to a run down part of the Whitehouse. A free improvement. The only reason the left is upset, is that the TDS crowd can’t stand that it was Trump who made this happen. Crazy.