"Argue with conservatives"? Folks are poking fun at someone for making a silly mistake; it literally happens all the time - there's no "argument".
To recap: someone poked fun at POTUS' for making an elementary geography mistake and most people laughed (as normal people do, regardless of political affiliation) - just like they laughed when Obama (or literally any other POTUS) made a gaffe of their own. It happens - it's not the end of the world.
The issue here isn't the folks poking fun at a harmless mistake.
Rather, the issue is the people who, a.) must contort truth/reality in order to defend POTUS from a silly geography gaffe, and/or b.) see those who are poking fun at said gaffe as being unfair/harsh persecutors of POTUS.