I live in Oregon, the ONLY state where euthanasia is legal.
We have voted in favor for it twice (to make it legal, and then when a petition to stop it came up) approving it both times by a somewhat wide margin, and have defied the Attorney General of the United States, even when he threatened to sue every doctor who's ever performed the procedure. However, when John Ashcroft stepped down as Atty. General a while back & Alberto Gonzalez took over, the Justice Department has not pursued the case.
It should be legal, for those who want to use it. I, personally, would have a hard time deciding, but I hope I will never be in such a situation. However, many do wish to use it to end their lives, and I respect that decision. If they wish to go quickly & painlessly, and not leave behind large medical bills for their family to pay, that's okay. If doctors are uncomfortable administering it, that's okay, they can choose not to do that as part of their practice.
Just because people object to euthanasia, doesn't mean it should be illegal. I don't like it when people smoke, yet I am not getting petitions signed to ban cigarette sales. All cigarettes do it kill you, just like euthanasia does, except euthanasia is quicker & less painful. If someone who objects to it does not which to use it if they become terminally ill, they do not have to. It's a choice that needs to be made by each person in that situation individually.
So yes, I think it should be, and for where I live, it is.