So, as I feared, East Dunbartonshire MP Jo Swinson has been elected leader of the Liberal Democrats at federal level (but rest assured that Willie Rennie of "Winning With Willie" fame is still very much leader of the Scottish branch). The reason I say "as I feared" is partly because I'm not Swinson's greatest fan, and we'll now be subjected to her dripping-with-insincerity musings even more frequently, but it's also partly because there's some evidence from past history that having a Scottish leader can help the fortunes of a London party in this part of the world. For example...
* In the only general election Gordon Brown fought as leader in 2010, Labour took a hammering south of the border, but in Scotland held all its seats and actually increased its share of the vote.
* The 1974 Liberal surge under Jeremy Thorpe wasn't fully replicated in Scotland, but the Alliance surge in 1983 was, and by that point the Liberals were led by a Scot (David Steel). In 1992, the first election after Steel stepped down, the drop in the Lib Dem vote was greater in Scotland than it was elsewhere.
* In 2005, the Lib Dems under Charles Kennedy unexpectedly overtook the SNP to finish second in the Scottish popular vote.
The Kennedy example is interesting, though, because he was also leader during the 2001 election, when the Scottish Lib Dem vote increased but there wasn't the same scale of breakthrough. He was also federal leader during the 2003 Holyrood election, when the Lib Dem vote more or less flatlined. So that suggests any Swinson effect might be limited to Westminster elections, and might also depend to some extent on the platform she's given by the media. The reason that Kennedy did better in 2005 than in 2001 is that in the intervening period he had emerged as the leading voice in opposition to the Iraq War. If Jo Swinson similarly comes to be seen as the leader of the anti-Brexit resistance, that could be mildly worrying for the SNP. The good news is that she's running out of time to reap that potential benefit - what does she do if Britain leaves the EU before the next election? She may be able to get away for the moment with "wanting Scotland in the Yookye, and the Yookye in the Eeyowe", but unless she's going to argue for the Yookye to rejoin the Eeyowe (which nobody would believe anyway), she'll run out of road with that line after October. Pro-Eeyowe Scots will have to start looking towards independence as the only realistic way forward.
In my forthcoming article for next month's iScot, I'll also be making the point that even if there's a Lib Dem surge in a pre-Brexit election, that could actually benefit the SNP if it falls short of a certain threshold. For example, if pro-EU unionist voters in a seat like Gordon abandon the Tories and return to the Lib Dem fold, but not in sufficient numbers to actually take the seat, the obvious beneficiary would be the SNP.
That said, I'd suggest the SNP should keep a close lookout for any indication that the broadcasters are going to stitch them up by running three-way Johnson-Corbyn-Swinson debates during the election campaign. That would be almost impossible to defend, both on the basis of past precedent and the current state of the parties in the Commons, but you can guarantee that they'd try it if they thought they could get away with it.