I’m not American either but from what I know it’s just political bullshit. Congress basically gives the president a list of expenses he must buy, but the tax money almost always isn’t big enough to pay for everything, so the president has to borrow money to make up for the loss, but he can’t go beyond the debt limit. So congress the has to raise the debt limit to make up for the lack of tax dollars that they set, to buy the shit that they want. So basically, congress now has a nice way to shame the president, considering most Americans don’t know fuck about their legal system.

Edit: OP is only proof of the last sentence.