Is Past Imprisonment a Bar to Attaining Citizenship?
Past imprisonment is typically not a bar to attaining citizenship unless the severity is high enough to fall under a certain category such as aggravated felony. Typically, the person actually spends five years in jail, and then more likely than not, that would be an obstacle to obtaining citizenship.
A candidate has to be completely honest when applying for naturalization and filling out all the forms. Any type of run-in with law enforcement has to be fully declared on the application. For example, someone may be convicted of a crime and subsequently, their conviction has been expunged. For immigration purposes (which falls under federal law), that conviction still stands. Therefore it still needs to be disclosed on the application.
Having a DUI or a DWI typically in itself is not something that prevents an alien from applying to become a naturalized United States citizen. However, not disclosing this fact may (and most likely will) prevent you from becoming a United States citizen. But simply having a DUI or DWI conviction on its own is not a valid basis for having your naturalization application denied.