Can I withdraw a guilty plea?

Possibly, and the standard depends on when you ask.

Before sentencing, the standard is more forgiving — good cause. Courts consider whether the plea was truly voluntary, whether counsel's advice was adequate, whether new information emerged, and whether the State would be prejudiced.

After sentencing, it becomes substantially harder, generally requiring a showing of manifest injustice, and there are strict time limits for filing.

What supports withdrawal: a plea entered without understanding a direct consequence, counsel who gave incorrect advice about something material — immigration consequences being the recurring example — a promise made outside the record that wasn't kept, or a genuine claim of innocence with a reason the plea was entered anyway.

What generally doesn't: a change of mind, dissatisfaction with the sentence imposed, or a belief the deal could have been better.

The colloquy transcript is the obstacle in most of these motions, which is why what gets said at the plea hearing matters so much.