Why was Magneto so stupid?

For a guy with 'genius intellect' as they're always telling us, he makes some reallllly poor decisions. Like, almost all of his decisions have been pretty bad. Magneto was born wearing a pair of Bad Idea jeans.

Perhaps you're right, but his intention first and foremost was to send a message of intimidation to the rest of the human world, and the president stepping forward only to get shot would certainly raise the profile of his broadcast. This way, he can give the public a martyr that exemplifies the seriousness of his word, whereas he would be less convincing if he just opened fire on the whole cabinet without a second thought. He could be mistakenly branded for a psychopath instead of a "terrorist", which wouldn't help spread his ideology at all.

Because in that new Xmen timeline, Charles is a wimp and Magneto is a moron.

Guess that's what happens when you cast pretty people.

For every lie I unlearn I learn something new - Ani Difranco

He's been in jail for a while. Maybe he doesn't know Nixon all that well.

Also he was likely planning to execute everyone in the bunker anyway (he certainly would never have left Trask alive under any circumstances), so he didn't really care what 'Nixon' had to say to him or the cameras. Just let him say some last words, then bang.

Also, throwing a bullet by using magnetic power is not going to hit as hard as if it's being SHOT from a gun. The bullet should never penetrate, it should just harmlessly bounce off. It's like throwing a small rock at someone and expecting it to penetrate their clothes and skin. There's a reason why guns are super loud and use EXPLOSIONS and carefully crafted barrels to maximise the velocity and speed of the bullet so it can impact with maximum power. You can't generate ALL that just by a wave of hand that controls some magnetic force!

Even if you assume you CAN, there would be a really loud sound as the bullet reaches the speeds necessary to penetrate by breaking the sound barrier (which is partially why the gunshot is such a loud sound)! You can't just have Magneto wave his hand and have a bullet hit someone as the result, you have to generate enough velocity AND make the bullet 'twirl' AND make somehow sure it flies straight (if it curves, it loses speed and can't penetrate again) AND SO ON.. and you absolutely need that super loud 'sound barrier breaking' sound, which doesn't happen.

The bullet should bounce off, like a piece of gravel someone throws at ya, it's not gonna penetrate no matter how hard it's thrown. Sheesh.. these movies are so stupid.

he thought Nixon was under the effect of adrenaline