Regarding the social care proposal, I don't think calling it a "dementia tax" is very helpful. My mother lived to 97. She didn't have dementia but for the last few years she needed more help than I could provide so she moved into a care home. The vast majority of people who live to advanced old age will need some kind of support whether they have dementia or not, and it will need to be paid for. My mother's house was sold to fund her care and I was absolutely fine with that - it was her needs and her money. I put no money into that house and had no right to expect the state to contribute to "preserve my inheritance". An inheritance is what's left over after someone's lifetime needs have been met and £100,000 allowance seems a more than generous way of meeting people's wish to pass something on to their children, especially since the children of very old people will mostly be in their 50s or older and should have sorted themselves out by then.
As we all (hopefully) live longer the need for social care will increase and it will have to be paid for. For those with assets they should pay for themselves, and the state should provide care for those who can't afford it. The best way to fund this is surely by taxing people after they and their partner are both dead. My only reservation about this is how it is going to be implemented and how loopholes can be plugged. I would prefer a massive increase in death duties but that is probably politically impossible and lacks the hypothecation element of the current proposals.
As a natural Labour supporter , I am dismayed by the Party's negative reaction. There should be scope for a cross party consensus on this issue.