If the Rebbe declared himself to be mashiach, could we entertain the fact he made a mistake? Even Rebbe Akiva who had a mistaken hava amina that Bar Kochba was the mashiach? Rebbe Nachman zt”l spoke about how even the biggest tzadikim can make mistakes. He himself told one of chassidim who was wearing a certain coat that he would greet the mashiach in that coat. At a later date he said mashiach’s arrival wouldn’t take place for at least another 100 years. That same chassid asked, “But Rebbe – you told me I would greet mashiach in this coat!” Rebbe Nachman replied, “That’s what I said then, this is what I’m saying now”.
Maybe the Rebbe will have techiat hametim and be mashiach, but until that point in time comes the fact remains that up until now he hasn’t fulfilled the requirements the Rambam listed to qualify as mashiach so why does that make him any better a candidate than any other niftar tzadik? If I remember correctly, when the gemara speaks about the possibility of mashiach being from among those already dead it says if it is so then it would be Daniel hanavi. So if we want to talk about candidates from among the dead shouldn’t we give preference to the one the gemara itself listed?
All the above is assuming the Lubavitcher Rebbe did indeed proclaim himself to be the mashiach. I’ve heard a lot of spiritual algebra that he said so (the nasi hador is the mashiach and the rebbe was nasi hador so x+y = z) however are there any sources the pro Rebbe is mashiach camp can provide us where he straight up said it (i.e. a mamar written somewhere or a video recording of him saying so). Like not just people singing it and him smiling at them but he himself actually saying it b’ferush?