When I challenge majority democracy, many people leap to this idea that the issue is that the arbitrary number of people who must agree with the policy is simply too low. If we move to 50%, 80% or 99% then we will have a far better set of rules, but the 'consensus' model is fundamentally flawed from the start.
One of the devices the left like to use in debate is emotional blackmail. Instead of addressing your point, they will simply try to assert that you are immoral or that you are deliberately voting for / pushing morally reprehensible policies without truly considering the context within which policies need to be made. This is one of a number of techniques the left use to shut down debate which they don't want to partake in.
To give an example, let's say you're talking about pushing a campaign to lower the local housing allowance of housing benefit (which, frankly, is pretty high in some areas of the country - £250 a week for a 1 bedroom property). Instead of trying to reason with you about why the campaign is wrong (maybe it would make it harder to find affordable housing for recipients), nine times out of ten they will just try to shut down the debate with the following (or a variant thereof):
"You just want to give more to the rich bankers and take away from the poor!"
Of course, there are several issues with this statement. First of all, it's backwards, as we're not giving anything to the bankers or taking anything away from the poor. The natural state without government would be that the poor get nothing from the state, and the banker gives nothing to the state, therefore we are still suggesting taking away from the rich and giving to the poor, but "you just want to take away less from the bankers and give less to the poor, but still enough to rent a house without going to work" doesn't sound quite as powerful, does it?