Padilla was facing deportation after pleading guilty to drug distribution charges in Kentucky. He had been a Lawful Permanent Resident for over 40 years. Padilla argued that his counsel failed to advise him of the consequence of deportation before he entered his guilty plea. Counsel told him not to worry about deportation since he had lived in the U.S. for so long. Padilla argued he would have gone to trial had he known otherwise.
The Supreme Court held that changes to U.S. immigration law have made accurate and competent legal advice for non citizens accused of crime very paramount. The sixth amendment’s guarantee of effective assistance of counsel was therefore violated as Padilla was wrongly advised as to the consequences of his guilty plea. Read the full text; http://www.supremecourt.gov/Opinions/09pdf/08-651.pdf