Late last year the US satirical television show Saturday Night Live broadcast a sketch entitled the “Brooklyn Bubble”.

There, ran the script, it was “like the election never happened”. The Bubble was a planned community of “like-minded free thinkers – and no-one else”.

Reading some commentary over the past week I’ve been reminded of the Scottish bubble, one in which there’s no Tory revival, and where the current trio of Unionist MPs will all lose their seats at the forthcoming election, Alistair Carmichael because he leaked a memo, David Mundell via an SNP-Green pact, and Ian Murray because he’s failed to topple Jeremy Corbyn.

Even Nicola Sturgeon indulges in some classic bubble analysis: Tories are evil, naturally, and opposition to “hard Brexit” and the so-called rape clause will derail Ruth Davidson in both the local and general elections.

Beyond the bubble, of course, things look rather different, as shown by yesterday’s polls putting the Scottish Conservatives on either 28 or 33 per cent of the vote, levels last reached in the 1970s.

Now I remain sceptical this will translate into a dozen seats come 8 June – swings are never uniform across 59 constituencies – but it’s perfectly possible the hitherto “toxic” party could get around half a dozen gains. For the first time since the 1992 general election, Conservatives have a credible stake in this election.

And, interestingly, the sort of constituencies in their sights are those last held at that contest, when John Major hung on as Prime Minister against the odds and even modestly increased his party’s share of the vote and number of seats north of the Border. Then as now, the commentariat had predicted a “doomsday scenario” in which no Conservatives remained in Scotland.

There are other similarities, chiefly the Unionist dimension. In 1992 Major mounted his soap box with a “save the Union” battle cry, and a quarter of a century later Ruth Davidson will be pursuing a similar tactic with her opposition to a second independence referendum. The revival that began at last year’s Holyrood election looks set to continue on 4 May and 8 June.

Of course part of it is a Unionist rather than a Conservative vote, disaffected Labour voters who see Ms Davidson as a more credible bulwark against the SNP than Kezia Dugdale. But that isn’t the whole story. Back in 2013, Lord Ashcroft conducted an extensive survey of Scottish political opinion and found around a third of the electorate could potentially vote Tory as long as it wasn’t going to be a wasted vote.

So judging by yesterday’s polls – which senior Scottish Tories are sensibly treating with caution – that potential Conservative vote is being augmented by non-Tory voters “lending” their support to fend against another referendum. That, therefore, puts several SNP-held constituencies in contention, the sort of places the party picked up at last May’s Holyrood election. Ruth Davidson is even encouraging the sort of tactical voting her opponents once urged against Tories in the 1987 general election.

And if Unionist voters take her advice then it seems likely Labour’s Ian Murray will be safe in Edinburgh South courtesy of tacit Tory support, and in East Dunbartonshire, where Liberal Democrat Jo Swinson stands a good chance of reclaiming her old seat from the over-rated SNP incumbent John Nicolson.

As today’s Herald story confirms, the bubble analysis is mistaken on a number of fronts. The Prime Minister’s hard-line approach to Brexit (or indeed her referendum "veto") hasn’t driven up support for independence, and nor is the idea of a “hard” Brexit that toxic among voters who generally don’t like freedom of movement. Outside the bubble, Nicola Sturgeon is also increasingly divisive, particularly among older female voters, while Mrs May is viewed relatively positively.

At the same time, Tories should exercise caution, both nationwide and in Scotland. Talk of 1980s-style three-figure majorities seem premature, while even on a big swing the sheer size of many SNP majorities will make recapturing long-lost seats like Perth and North Perthshire extremely difficult.

Still, given the Scottish Conservatives’ poor showing at every UK general election since 1997, even a trio of gains will look like considerable progress, and the Prime Minister needs at least that for her “now is not the time” line on a second referendum to hold up. Vote shares will be crucial to the battle of mandates; the total “Unionist” vote in Scotland will require a significant increase to bolster the argument that demand isn’t there for a re-run of 2014.

Angus Robertson, the SNP’s Westminster leader, wasted little time last Tuesday in framing the election as a “two-horse race” between his party and the Conservatives, which was music to Tory strategists’ ears. Changed days indeed from when all Nationalists had to bother about was defeating the Scottish Labour Party.

The SNP’s sophisticated polling operation is of course aware of the Tory revival and (relative) popularity of Ms Davidson, thus the ongoing attempt to re-toxify the Conservative brand through vilification over the rape clause. “The bigger the Tory majority,” the First Minister will tell today’s STUC conference in Aviemore, “the more they will think they can do anything to Scotland and get away with it.”

Only the SNP, runs the argument, will have the “strength” to “stand up” to the Tories and “make Scotland’s voice heard”. That begs the obvious question of how? At the 2015 election the SNP looked like a credible king-maker, something that doesn’t apply this time round. Suddenly that old 1987 taunt about Labour’s “feeble 50” MPs could come back to haunt them.

The Nationalist response also demonstrates that they’ve been wrong-footed twice by the Prime Minister in a matter of weeks. First, they wanted another “progressive alliance”, then they didn’t, then they wanted to keep the Tories out nationally but not locally, a position difficult questioning meant they had to “clarify”. And while the SNP might not want this election to become a referendum on a referendum, the First Minister probably won’t have much choice given that’s all she’s been talking about for the past few weeks.

Inside the bubble, it might look like Scotland’s on course to be a 1997-like Tory-free zone, but back on planet earth the tectonic plates of Scottish politics are moving once again.