Can a defendant withdraw a guilty plea for good cause before the entry of judgment?

"A defendant may move the trial court to set aside a guilty plea for good cause at any time before the entry of judgment. (Pen. Code, 1018 . . .) 'Good cause' means mistake, ignorance, fraud, duress or any other factor that overcomes the exercise of free judgment and must be shown by clear and convincing evidence. [Citation.] The grant or denial of such a withdrawal motion is 'within the sound discretion of the trial court and must be upheld unless an abuse thereof is clearly demonstrated.' " (People v. Ravaux (2006) 142 Cal.App.4th 914, 917.)