Regardless of what you think of the Dems and GOP, this shit is image poison for the GOP. Right now, more voters are blaming the GOP (52%) than the Dems (42%). It doesn't matter to voters that what is going on with the White House is privately funded (and on a different scale, the entire renovation could fund food stamps for maybe a day or two).
It's terrible optics. Building a $200M ballroom at the same time that food stamps are being cut (for the record, they should be cut, food stamps are an antiquated relic from the Depression and have no business being used today) is going to be a big, big, BIG weapon for the Dems to use for the midterms in one year. It literally does not matter whether it really is or is not the Dem's or GOP's fault. What matters is that voters are seeing it as the GOP's fault, and the GOP being so wildly opulent during a time that shit is being shut down and cut is going to be bite really bad in the upcoming midterms. That basically makes the Dem platform right there.