Oh, it still happens. Granted, I can't think of a recent example in the UK and the US but if you're willing to look outside that box and just off the top of my mind: The Netherlands. Pim Fortuyn.
Good memory, but again did anyone describe this as 'inevitable'. Fortuyn was killed by one freak, probably acting alone, in a country with free speech rights. Those rights have not changed as a result of his assassination. Yes, there are political killings in EVERY country, but again I think the main difference with this one in particular was that it has been described as 'inevitable' from the moment she landed back in Pakistan. She certainly didn't help herself by standing up in the sunroof of the vehicle despite the advice against it, but she wanted to stand up freely for her supporters and for her cause.