Why do some Republicans believe that catering to illegal aliens will help them win elections?

McCain introduced legislation with his name on it in 2007 that would have allowed massive chain migration, de facto amnesty and a massive flood on the southern border but he did not win the election even though he got the nomination. The pundits say that the Hispanic vote is massive and needs to be catered too, but that is premised on the idea that Hispanic voters agree with illegal immigration. What do you think?