Is this fancy dress idea bad taste?

[Miyajima98]

Is it bad taste to dress up as Donald and Melania Trump for a Villain themed halloween party? (assuming of course that everyone there will be left leaning and definitely not supporters...)

I thought it would be quite funny but then I saw an article saying that it was in bad taste due to "normalising" their behaviour...

Depends on the company. Most people I know would find it hilarious including myself. But in today's world your could dress as a Disney character and there would be someone out there waiting to be offended.