She's done it though by tapping into the pro-EU views of the Scottish electorate: she's fanatically pro-EU and is already trying to push May into a softer Brexit. I agree that she'd give Labour a tough battle (she's probably the one leader they fear) but I can't see her being elected.
Even if...
Douglas Home was an interesting case: he was a peer of the realm but resigned his earldom on being appointed leader, he then stood for the vacant seat of Kinross and West Perthshire and duly won it about three weeks later. But for three weeks, he was PM but neither peer nor MP. That wouldn't...