but there is a large population of Britain who feels the same way
Where is this large population in Britain who feel the same way? I live in Britain, I've been a journalist for 20 years and I certainly don't see this "large" population.
There's a small vocal minority, usually among the republican political parties like Alec Salmond's Scottish National Party but most polls on the street don't wish to see an end to the Monarchy at all.
In fact, given the whole farcical situation in recent years with the Tony Blair/Gordon Brown Prime Minister situation, I suspect the number of people who'd like to see an elected Head of State similar to the US has gone down even more.
The amount of people who, inaccurately, state they "didn't vote for Gordon Brown" as Prime Minister (given that, unless they live in Sedgefield, they didn't vote for Tony Blair either as we don't elect our Prime Ministers they are chosen by the Political Party in power) has also risen in the last few years.
In addition, Charles' reputation has risen over the last few years as he has begun more and more to take on an elder statesman role and the recent BBC documentary on him at 60 has, the same as the recent one about Anne at 60, thrown new light into their personalities and sense of humour etc.
I think anyone writing off Charles not only becoming King but being a well loved and successful one, outside of the small Republican minority in the UK, are hugely mistaken.