I'm not surprised (although North Thanet has been held by Roger Gale for the Conservatives since 1983), but it has changed in the last 24 years. More and more people seem to be having to travel to work, meaning they are away from home longer, some are having to take on second jobs, they are not necessarily living near their relations (who would be able to support them), there is the uncertainty of job security in some cases, they come home and are tired. Its a box-set and a take-away.You might be surprised - in 1997 Labour had:
Dover
South Thanet
North Thanet
Sittingbourne and Sheppey
Medway (now Rochester)
Gillingham
Gravesham
Dartford
So almost a continuous string from Dover to London, in the towns which in recent years have been the poorer half of Kent. Admittedly that was the largest landslide but they were winnable once. That would have been with a higher proportion of home ownership and fewer renters as well.
I don't know why you assume that people who move to Kent because it's cheaper than London would be 'uninterested in politics' - if anything they would have more reason to vote against the government?
I did say that there are not really interested in politics, so Labour has to have policies that affect them directly, draw them in, get them interested, but something realistic, not like Corbyn's free broadband desperation measure. As an example, Blair introduced the minimum wage in 1999, the same government set in statute 18 weeks paid maternity leave. Directly affecting working people for the better and opposed by the Conservatives. Instead it is easy to taint Labour with madcap policies because one or two on the extreme left have blurted them out. As I wrote earlier Emily Thornberry's post hurt big time. Maybe they need to ask these people want they want, not just activists or interns - something concerning rights for those in the gig economy might be helpful, as the Tories will oppose it. I have no idea if it is possible but try to restrict the steep rise in house prices, all that happens now is the tax payer effectively pays money to the developers through stamp duty holidays and the like that enable prices to be jacked up. One problem is that our Prime Minister (and his predecessors) have pinched some of Labour's ideas - Living Wage, yea, right; green agenda (lots of targets to be met by someone else).