I was for the introduction of US style primaries for British elections before I was against them. Actually I'm not wholly against them but think that they are overrated as a method of weakening the control of the political parties and encouraging voter engagement.
First of all our parties aren't going to completely open up, it's going to be a Henry Ford style choice- vote for any candidate you want as long as it is a Central Office approved drone. Secondly with low voter interest it would be quite easy to distort the process if a candidate has enough connections. Thirdly almost all of the benefits can and none of the downsides of primaries can be achieved in another way- by having a Single Transferable Vote system, as they have in Ireland, where you have multi member constituencies and ranked voting. This would create space for smaller parties to exist and offer a real choice, it would mean that you could still vote against a candidate even if you want to support their party and no one could say that their vote would be wasted.
Victory for decency in Alabama
1 hour ago