Karachi has had an overdose of history, too much has happened.

Karachi captures all of those rifts between ancient and modern, communal and individual. You see them playing out in people's lives.

We have to remember in that Bloomberg poll, strong Republican support for [Donald ]Trump's proposal, but the country at large - strong opposition to that support.

I have reported enough about Islam and terrorism to recognize that a lot of what is at stake is not strictly religion, even though it's also about power and control. In the case of Karachi, like so many other growing cities, it's also about land, mafias, gang activity.

I would say that the one incredible thing that Karachi has going for it is the unabated supply of new migrants that pour into it day after day. It could be a poor factory worker who simply wants a job, it could be an ambitious guy coming for an education - they all add hope and vibrancy to the city. Now, this is not something that is generally taken as positive in Karachi. But the hope is that the migration that comes into the city replenishes its stores of resilience and energy.

I do know that a law professor there [in Columbia University] published an article calling me a white supremacist.

In this country tonight, PBS shows one of the most talked about tributes of the year.