If you want to understand why Labour confounded the polls in 2017 - preventing Theresa May from winning a Commons majority - look no further than Cheshire.
Before that snap general election just the spout and lid of this teapot-shaped county were red, including the party's most marginal constituency in Chester.
In the end, their majority in the county town soared from 93 to more than 9,000.
To add insult to injury, they took three more seats from the Tories - Weaver Vale, Warrington South and Crewe & Nantwich (which they won by only 48 votes).
Labour were able to inspire thousands of people to go to the polls who don't normally come out to vote. In Chester, for example, the overall turnout rocketed by 5,000 but the Conservative vote didn't move.
The city was flooded with Labour placards and doorknockers. I'm told turnout at the polling station used by the University of Chester's 10,000 students was significantly up, which it's thought helped Jeremy Corbyn.
But Labour also seems to have benefitted from a lack of smaller competitors - in Weaver Vale, Warrington South and Chester UKIP didn't stand in 2017, whilst there was no Green candidate in the latter two as well as Crewe & Nantwich.
What about the Lib Dems?
The Liberal Democrats could have a key role to play in marginal Warrington South, which was a three-way split back in 2010.
Conventional wisdom might assume the Lib Dem vote then went to Labour and so could go back now. But Lib Dem support at council elections is centred on the relatively affluent suburbs and villages south of the Manchester Ship Canal, so the party could threaten the Tories too.
Jo Swinson's party has a well-worn infrastructure there, where they've been campaigning against the Labour authority's plans to build 9,000 homes on greenbelt land, whilst attacking the Conservative government's guidelines which the council must work to.
If they are being optimistic, they might even be looking towards the apparently safe Tory seat of Congleton. The Lib Dems used to run the borough council there and took 31% of the vote in 2010.
The Brexit factor
Both Labour and the Tories could also have much to fear from the prospect of Brexit Party candidates standing in non-Conservative-held seats.
They came a clear first in the European elections in the boroughs of Halton and Warrington, suggesting they could damage Labour in their traditional heartlands in seats like Halton, and Warrington North. Crucially it could make a key difference in Runcorn within the marginal seat of Weaver Vale.
In Crewe & Nantwich many former UKIP voters seemed to go back to Labour in 2017. Will Mr Corbyn doing his utmost to keep Leave voters from working-class Crewe communities onside and away from the Brexit Party and the Conservatives be enough?
At the same time the Labour Party knows it needs to reach out to Conservatives in places like Nantwich. Two years ago it scored very well with a high-profile campaign about school funding.
Another campaign issue that the Conservatives may hope to have neutralised is fracking - opposition to it was successfully harnessed by Labour in the Weaver Vale constituency two years ago.
Parts of Ince Marshes near the traditionally Conservative areas of Frodsham and Helsby have been targeted by energy firms for the last two years, and earlier this year the vehemently anti-fracking Greens unseated the Tories in Helsby at the council elections.
The Conservatives have now called a halt to fracking, while Labour and the Liberal Democrats have advocated a permanent ban.
All eyes on Eddisbury?
One place that is not normally interesting to watch come election night is the usually safe Conservative seat of Eddisbury - the rural heart of Cheshire plus the town of Winsford - which was finely split in the EU referendum.
The sitting MP Antoinette Sandbach was thrown out of her party after rebelling over Brexit and has now joined the Liberal Democrats.
She got 29,192 votes last time and her new party got just 2,804. So she has a mountain to climb but we know there are a lot of Remain voters there who seem to have voted Conservative last time round. She will be hoping to unite them behind her.
Labour did extremely well in Cheshire two years ago but holding on to its existing seats in the county may well be their limit this year.
To take Macclesfield, a town that has been represented by the Conservatives for more than 100 years, Labour would need to repeat the 7% swing from the Tories that they managed two years ago.
A hard but not impossible task, perhaps. But if they manage to paint the likes of Macclesfield red, Mr Corbyn may well end up in Downing Street.