If you do the crime, and you end up with time, then it is easier to be denied all relief. This reason is usually the really messy one, but the DHS has to prove it. If proven, then there is usually no relief unless you are a U.S. Citizen without knowing it (possible)! Talk about the Convention Against Torture with an experienced attorney before you decide to go forward with the claim.
Not all state felonies are aggravated felonies for immigration purposes. There is this big list, but an attorney has to read the actual criminal statute in effect at the time that the offense was committed. The words in the statue, and the state where the conviction took place can affect whether the felony is actually an aggravated felony for immigration purposes. The region where the Immigration Court hears a deportation case can also have an impact!
A Crime Involving Moral Turpitude
Those crimes that require intent, knowledge and worst of all, sin, in the opinion of the Federal Government as interpreted by the Board of Immigration Appeals and the Federal Courts. It has been a sin to use cocaine for 14 years according to the Board of Immigration Appeals. Sometimes, these sins are forgiven, but you need provide good reasons why the Immigration Judge should forgive you. Otherwise, the Judge does not have to grant cancellation of removal.
Aliens Previously Removed
If you did not get advanced permission to re-apply, then your deportation order may be reinstated if you re-enter without inspection. This means no hearing unless there is a mistake or you fear return on account of persecution. If you have been deported, then you can be swiftly removed. The hearing already happened! You've been there, done that. Marriage to a U.S. Citizen usually no longer helps.
Registering to Vote or Voted
Registering to vote usually requires you to present yourself as a U.S. Citizen in violation of a state or Federal law. Violating a State's Constitution by voting, when you are not a U.S. Citizen has been considered arguable sufficient for a deportation order in the opinion of the DHS. Salvation can come in the form of cancellation of removal, where an applicant qualifies as a matter of Immigration Judge discretion.
Commiting a Crime at a Port of Entry
The international terminal is not a good place for a lawful permanent resident to beat someone up over baggage or get irritated over some pointless argument, then accidentally kill them. Getting caught delivering or possessing large quantities of controlled substances, as in drugs (yes cocaine and marijuana, as well), is unwise. Yet, it happens and more often than you would imagine.
A Mental Disorder or Behavior Associated with a Disorder that Poses a Threat to Safety
Hmm. What does this mean? Well, I would definitely discourage clients from doing their impression of a CIA Agent, Chairman Kruschev during the JFK Years, or the Shoe Bomber in front of the airplane tray tables and windows of their 747 en route to JFK Airport. Perhaps, Donald Duck might be okay as long as you don't try to fly out one of the doors or windows.
Admitting a Crime at a Port of Entry
The CBP can take a lawful permanent resident into custody where a returning lawful resident admits facts which constitute a crime that can result in inadmissibility under Section 212. Nope, a CBP officer is not the best sin bearer. If you get caught at the international terminal airport, a port or other inspection points, then you can be found inadmissible and removed.
A Drug Addict or Abuser
There must be a determination of actual abuse (or so we believe), so some applicants may be overlooked until arrest, conviction or rehabilitation, whichever comes first. Of course, we prefer rehabilitation, since it is less likely to result in an unhappy ending.
Serving in a Federal or State jury
Serving in a jury requires you to 'present yourself' as a U.S. Citizen in violation of a state or Federal law. This does not mean that you insist you are a U.S. Citizen. Violating a State's Constitution by serving in a jury, when you are not a U.S. Citizen may be considered sufficient for deportation order as a matter of law. Salvation can come in the form of cancellation of removal, where an applicant qualifies. Speak to a supervisor and even tell it to a judge; lawful permanent residents cannot serve on a Jury!
Money Launderers, Prostitutes, Terrorists, and Intentional Polygamists
Is there any need to explain? Well, former prostitutes may not have an issue. If you somehow did not know that you were married to someone else, were unsure (she said she divorced you), or did not intend to have a life with two wives, then this should be dealt with in Court before you take any action.
And one more--Registering and Serving as a Notary Public in Illinois at a Minimum
This is a rare but more recently emerging issue of concern. In Illinois, you must be a U.S. Citizen to register and serve as a notary public. If you falsely represent yourself to be a U.S. Citizen, by filing out the application without reading the instructions, then you have arguably created a reason to be deported based upon INA Section 212(a)(6)(C)(ii). This becomes arguable, but it involves an arguable false claim, never verified by the State of Illinois, once the application is completed.