Fourteenth Amendment, Section 1:
All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.
A defendant may plead guilty instead of insisting that the prosecution prove him guilty. Often the defendant does so as part of a
plea bargain with the prosecution, where the defendant is guaranteed a light sentence or is allowed to plead to a lesser offense. 1 Although the government may not structure its system so as to coerce a guilty plea, 2 a guilty plea that is entered voluntarily, knowingly, and understandingly, even to obtain an advantage, is sufficient to overcome constitutional objections. 3 However, some constitutional challenges may survive a plea if they go to "'the very power of the State' to prosecute the defendant."  4 The guilty plea and the often concomitant plea bargain are important and necessary components of the criminal justice system, 5 and it is permissible for a prosecutor during such plea bargains to require a defendant to forgo his right to a trial in return for escaping additional charges that are likely upon conviction to result in a more severe penalty. 6 But the prosecutor does deny due process if he penalizes the assertion of a right or privilege by the defendant by charging more severely or recommending a longer sentence. 7
In accepting a guilty plea, the court must inquire whether the defendant is pleading voluntarily, knowingly, and understandingly, 8 and
the adjudicative element inherent in accepting a plea of guilty must be attended by safeguards to insure the defendant what is reasonably due in the circumstances. Those circumstances will vary, but a constant factor is that, when a plea rests in any significant degree on a promise or agreement of the prosecutor, so that it can be said to be part of the inducement or consideration, such promise must be fulfilled. 9