If you are a U.S. green card holder (lawful permanent resident) or other immigrant, and you were charged with a crime, your criminal defense counsel may have been trying to help by recommending that you plead guilty to a charge. Perhaps by pleading guilty, and thus saving the prosecutors the hassle of a trial, you were given a reduced sentence or no jail time.
Unfortunately, few criminal defense lawyers understand the complexities of the U.S. immigration laws. You would not be the first to discover the hard way that having a crime on your record can result in Immigration and Customs Enforcement (ICE) beginning deportation proceedings against you. Sometimes even a minor crime, such as a misdemeanor, can be classified as an "aggravated felony" or a "crime of moral turpitude," both of which can have harsh immigration consequences.
Until relatively recently, the law's attitude toward the immigrant was, "Tough luck." However, that changed with the U.S. Supreme Court 2010 decision in Padilla v. Kentucky.
Mr. Padilla was a green card holder who was arrested for transporting a large amount of marijuana in his tractor/trailor, a crime. On the recommendation of his lawyer, he pled guilty to three charges, in return for which, two were dismissed. The lawyer not only didn't tell him of the likely immigration consequences, but assured him that he'd be safe from deportation because "he had been in the country so long" (over 40 years).
The lawyer must have known almost nothing about immigration law. Not only are drug crimes a ground of deportability, but no waiver (legal forgiveness) is available for cases where the deportation would cause extreme hardship to family members. (For details on this, see "How Will a Drug Crime Charge Affect Your Green Card?")
Mr. Padilla was placed in deportation proceedings, where he faced removal to his native country of Honduras. He then (with the help of a different lawyer) argued that his first lawyer's advice was an example of "ineffective assistance of counsel." He said he never would have pled guilty if he had known what would happen, and that the conviction should therefore be overturned.
While the lower courts showed little sympathy, and held that his conviction was a mere "collateral consequence," the U.S. Supreme Court disagreed. It said that deportation is indeed a "penalty" – a particularly severe penalty, no less -- and that therefore, the Sixth Amendment to the U.S. Constitution requires reasonable professional assistance to anyone facing such a penalty. Mr. Padilla did not receive that assistance, and so his case was sent back to the lower courts in Kentucky for further proceedings.
If you are facing deportation proceedings based on a guilty plea that you made without realizing the immigration consequences, bring this up with your lawyer immediately. It may still be possible to show, under the Padilla case, that you did not receive the effective counsel that was your constitutional right. You will also need to show that, if you'd only gotten better advice from your lawyer, the result in the criminal court would have been better – in other words, that you were "prejudiced" by the misadvice.
An experienced lawyer, preferably one that frequently handles cases dealing with the intersection of criminal and immigration law, can analyze the possibilities and help you develop a strategy for going forward.
Unfortunately, the Padilla case is not considered retroactive -- that is, you cannot use it to undo a past criminal conviction that is no longer subject to any appeals. This was an open question for a while, but settled by the U.S. Supreme Court in 2013, in a case called Chaidez v. United States.