Why are LibDem voters voting LibDem?

Last night we showed how a third of Labour voters have no faith in Ed, no faith in the party to keep the purse strings right and they didn't even think the party was on their side, yet they vote for them. All information is on the link >>> Why are Labour voters voting Labour?

But today when voters are asked who is best to tackle different issues in the UK we find that on average a half of LibDem voters do not rate their own party as being best for the job.

It begs the question why do they vote for them then?

YOUGOV 44% of LibDem voters don't think the LibDems are the best people to look after the NHS & 54% don't think they can tackle immigration
— General Election (@UKELECTIONS2015) September 16, 2014

YOUGOV 45% of LibDem voters think the LDs are not the best to keep law & order in the UK 48% also think they would be no good with taxation
— General Election (@UKELECTIONS2015) September 16, 2014

YOUGOV 32% of LibDem voters think LibDems are NOT the best to sort out the education system 53% also think they CAN'T tackle unemployment
— General Election (@UKELECTIONS2015) September 16, 2014

YOUGOV 44% LibDem voters didn't think LibDems could sort out the welfare system. 47% didnt think they would be the best to sort out housing
— General Election (@UKELECTIONS2015) September 16, 2014

  http://cdn.yougov.com/cumulus_uploads/document/6fxmd5mla2/YG-Archive-Pol-Sun-results-150914.pdf