A Directly Elected First Minister?

There is a very vitriolic attack on the Liberal Democrats by Simon Jenkins in today's Guardian, in which he suggests that the Liberal Democrats are the flotsam of 20th-century politics drifting on into the 21st and suggesting that the best thing that the party could do is disband, to fold their tent and go.

On the whole the article is an illogical rant by somebody who clearly has an axe to grind with the Lib Dems, but it does contain one interesting observation. Commenting on the way that the Lib Dems are refusing to go into coalition with either the Labour Party or the National Parties in Scotland and Wales (at the moment at least) Jenkins suggests that it would be better if the First Ministers were elected in the same way as the London Mayor or the President of France

It is a tragedy that in Scotland and Wales the executive is chosen from the parliament, as at Westminster, but from one composed by PR, thus virtually ensuring rolling coalitions. This was instead of the London option of a separate executive and assembly, which is the constitutional basis of devolved government almost everywhere. Scotland and Wales should have had directly elected first ministers, with proportionately elected assemblies to check them. This would have met the requirement for a strong government in Edinburgh and Cardiff and for proportional representation in the balancing parliament/assembly.

I quite like this idea. France and London use slightly different ways of deciding who the winner is, but they are both a variation on a theme that leaves two candidates in a run off in which the one who gains more than half the vote gets elected.

The intriguing thing is what would happen if such a system were used in Wales?

If the run-off were Labour-Plaid, who would the Tories support? The Unionist Labour party or Plaid in order to beat the Labour archenemy.

If the run off was Labour-Conservative who would Plaid support? Would they also want to Kick Labour into touch as one of their election posters declared or would they vote for anything that wasn't blue, even a Labour FM?