In the UK it was more a case of low voting.. traditional Labour voters .. Voted.. and the Traditional Tory voter not wanting to vote for people who have been inept for 14 years. So didn't vote
In the US.. It was Low voting... traditional Republican voters ., voted... Traditional Democratic voters couldn't bring themselves to go vote for a black woman. So didn't vote
The non voters couldn't see how either party would improve their situation... So why bother