The Lib Dems have targetted it because they assume that Henley largely relied on that of the popularity of Boris Johnson and they think that by going to this eccentric seat with a similar upbeat attitude they are trying to capture the seat on trying to exploit some weakness in the Tory Armour by snatching a similar "safe" seat.

However, Henley has been "True blue" since 1910 and is one of those genuinely unshakable seats much like say, Sedgefield which has voted Labour since 1935.

The Tories will still run a decent campaign, but nobody is really expecting any kind of change, it's just "one of those seats" where the constituents will mindlessly vote for whatever they put a blue rosette on.

Couple this with the recent surge in popularity with turning Crewe into a Blue-Washout zone [Tory Council, Tory MP in an area previously seen as a rock-solid Labour Safe zone] and the chances diminish further.

Fact is the Tories are running on a pretty much unstoppable juggernaught with a campaign that doesn't run on "What we'll do." like the Lib Dems and Labour are running on. It seems to largely be a campaign of "What do you want us to do?"

Their policy centre talks and investigates very carefully asking people from a wide range of backgrounds on their opinions and ideas. Since last year 1,000 pages of policy have infact been published by the IDS's Policy Think Tank as well as the other units the Tories have to plan for government. This is also shown in their "Agenda" documents on their site, with three real "base" aims in mind.

"(1) the principle that social goals can best be achieved through government setting frameworks rather than through government micromanaging provision;

(2) the principle that the energies of civil society can be mobilised by paying competing providers of socially beneficial transformations on the basis of the results they achieve; and

(3) the principle that, by acting in this decentralised, non-bureaucratic way, government can (so far from adding to the burdens on the taxpayer) progressively diminish the otherwise ever-increasing demands on the state."

Oliver Letwin 

It's this basic idea that is now appealing to masses of working class voters across the country and coupling it in with localized issues are also causing people to "tune in" and resonate with the resurgent Tory party. 

As much as it may be a boost to the flagging Labour and Lib Dem Popularity [Though recently polls say Nick Clegg has snatched a further 2% off of Labour] I wouldn't expect any kind of miracles from Henley. Not really "hubris" from a Tory such as myself but I really cannot see it happening. If anything it may mobilize more voters to vote for the Tories to boost their already large electoral successes locally and in the by-elections.  

 

I don't think the Henley by-election will be nerve-wracking for the Conservatives one little bit. That said, they will still campaign hard because the by-election provides another stage on which to speak to the wider audience of a future GE electorate.

The Liberals are clearly playing, not to win, but to merely be seen to be in the game.  Quite simply, for them its a "Hey look at us, we're a serious political force, just us and the conservatives". Recently they've been quick to promote themselves as 'the real opposition' and this showboating will further reinforce that - although I don't believe they'll convince anyone seriously.