My girlfriend is from Mexico, and we live in California, where same-sex marriage is (yay!) once again legal. I’m a U.S. citizen. She, however, has no status in the U.S., having crossed the border illegally when she was in her early twenties. If we get married, can I help her become a U.S. citizen?
NOTE TO READERS: This Q&A addresses the legal situation before 2015, when same-sex marriage was legal in only limited U.S. states. As of the Supreme Court's June, 2015 decision in Obergefell v. Hodges, same-sex marriage is available in all 50 states. The remainder of the analysis is still valid.
Your question has several important legal aspects, which we’ll try to address separately here.
First, the matter of same-sex marriage and immigration benefits: Yes, they exist, since the U.S. Supreme Court’s Windsor decision removed the bar to immigration rights for same-sex couples. The spouse of a U.S. citizen is an “immediate relative” in immigration law lingo, and therefore immediately eligible to apply for U.S. lawful permanent residence.
The important thing in petitioning for a same-sex spouse will be to make sure that the marriage is legal in the state or country where it took place – but as you say, California is currently allowing same-sex marriage. You will need to obtain a certified copy of your marriage certificate before moving forward with the immigration process.
Next, the matter of what rights a same-sex spouse gains: It’s too soon to talk about U.S. citizenship. The first step will be a U.S. green card, or lawful residence. In fact, with a marriage less than two years old at the time you submit the visa petition (Form I-130) to start the application process, your wife will gain “lawful conditional residence” as opposed to “lawful permanent residence,” and have to submit another application before the end of a two-year period to remove the conditions and become a full-fledged permanent resident. After three years of marriage and living with a U.S. citizen, a green card holder can apply for U.S. citizenship.
Now, to the most difficult part of your question: your girlfriend’s undocumented status. Because she entered illegally, and assuming she has been in the U.S. for more than six months, she’s likely got an inadmissibility problem, as described in “Consequences of Unlawful Presence in the U.S. -- Three- and Ten-Year Time Bars.”
That means that, although technically eligible for the green card, she probably won’t be allowed to stay in the U.S. to apply for it – though she can still apply for it at a U.S. consulate in Mexico – but it won’t be granted for three or ten years unless she qualifies for a waiver. And the waiver needs to be based on extreme hardship to her U.S. permanent resident or U.S. citizen spouse (that’s you) and/or parents.
See the “Inadmissibility and Waivers” section of Nolo’s website for details. You’re in a situation where may be no risk-free option available for your new spouse’s application for U.S. immigration benefits, which you would be best off discussing with an experienced immigration attorney.