Further to my past post on British Obamas? Yes we've had a few, a few other thoughts on the matter, this time on the problems in the US.
What is perhaps not realised so well is that the key barrier that had to be overcome to having a black President wasn't the Presidential election itself but in getting black politicians to credible elected positions - usually a Governor or Senator - from which they could then make a credible bid for the Presidency. FiveThirtyEight.com: Why Are There No Black Senators? and the resulting discussion thread looks at this problem in the US, with the conclusion that successive measures aimed to protect black voters have resulted at Congressional level in them being ghettoised into gerrymandered safely Democratic urban seats, with the result that black US politicians appear too left-wing for moderate swing voters and few Republicans have to make any appeal to black voters because there aren't many in their own seats. This in turn reduces the pool of potential Senate and Gubernatorial candidates who in turn could run for President. Obama got lucky in missing out a period in the House of Representatives (and it's easy to forget how during his Senate race practically everyone inside - and outside - the Illinois Republican Party seemed to falling over to remove any credible challenger to him) but it's going to take more to get a more permanent grouping of black mainstream politicians in both parties and enable black conservatism to gain a stronger voice. (And yes there have been black Republicans in Congress - the last was J.C. Watts who rose to the number four position in the House Republicans.)
The British system is very different and so far there is no route to the premiership other than service in the Commons. I can see London electing a black Mayor in the future (how about James Cleverly when Boris retires?) but I don't think we've yet reached the point where it's possible for a high flier in another political sphere to jump directly into front line politics in the Commons, unlike in Canada where provincial politicians and even private citizens often get chosen as party leaders. So it is going to come down to those who have worked their way up through the benches in the House and are sufficiently moderate to win the leadership. To take the first four BME MPs elected back in 1987 as examples, the likes of Diane Abbott and the late Bernie Grant would never make it, both being too far on the left of the party. Keith Vaz had a promising ministerial career but was derailed by sleaze. However I believe that if he had not become High Commissioner to South Africa, Paul Boateng would currently be one of the most senior members of the Cabinet and given Gordon Brown's succession of local difficulties Boateng would have been a credible potential candidate in all the leadership speculation and a darn sight more serious one than David Miliband and his banana.