During a recent concert, Dropkick Murphys singer Ken Casey trolled a fan that was wearing a Make America Great Again T-shirt and made a bet with him about the shirt's country of origin.

“These shirts, plainly and simply ... Israel Palestine Again in the style of President Donald Trump’s Make America Great Again hat was trending on Etsy. JTA has documented Jewish history ...

We also got to go inside the factory in Los Angeles County where the Make America Great Again hats are made ... The official Trump navy MAGA t-shirt, it's definitely the top seller.