how can I sponsor them to be here
You can send them an invitation letter and file for a Form I-134 Affidavit of Support, promising to cover theIr expenses while here, that could help if they are elderly and have no real income or properties to speak of in their home country. They will still have to overcome the INA Section 214(b) immigrant intent provision, but some US consulates are particularly deferential and respectful of elderly applicants, as they don't suspect they are coming to work..
If your parents are not already of retirement age it'll be harder for them to qualify for a visa, and the fact that their son or daughter was issued a visitor's visa and then managed to remain in the US through marriage or something else will not be helpful at all , unless one of them has a well paying job or business, properties and a good incentive to come back.
Behar Intl. Counsel 619.234.5962 Kindly be advised that the answer above is only general in nature cannot be construed as legal advice, given that not enough facts are known. It is your responsibility to retain a lawyer to analyze the facts specific to your particular situation in order to give you specific advice. Specific answers will require cognizance of all pertinent facts about your case. Any answers offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship.
If you want them only to visit you, you can help them apply for the visitor visa by going to the website of US consulate nearest them in your home country and fill out the required applications.
As alluded to by Atty Behar, their challenge will be to show they do NOT intend to remain in the U.S. They should go to their interview with proofs of employment, property ownership, long-term lease, investment assets, etc - whatever they can to show they plan to return.
Andrew M. Bramante, Rosner Partners, 216-771-5588. Free telephone consultation. You should always consult with an experienced immigration attorney to make certain that the advice you received is appropriate for your particular immigration case.
I agree with my colleagues.
Law Offices of J Thomas Smith J.D., Ph.D 11500 Northwest Freeway, Suite 280 Houston, TX 77092 713-LAWYER-2 www.MyImmigrationLawyer.info NOTE: Responses are for the education of the community at large and is not intended to be "legal advice." No attorney-client relationship is established by responses or comments.