The manifesto tried to do too much. It featured policies to appeal to the elderly, free broadband, the eradication of university tuition fees for students, and a promise to reduce the voting age to 16. In trying to make everybody happy, the manifesto made nobody happy.
Voters are not fools. They know that when a government enters office, it has a finite amount of political capital. It must use this capital to fulfil the most important policies of its election manifesto. This is why most parties put one or two signature policies in the manifesto. Labour's decision to include many big-ticket policies, including its free broadband policy, increased NHS funding, more spending on the elderly population, and the eradication of university tuition fees, only revealed the hollowness of the policies. Voters could see that the government would not have the political capital to bring all of these policies to fruition. By promising the world, voters knew they would deliver nothing. A large manifesto that attempted to do too much alienated many potential Labour voters in the 2019 General Election.
Labour’s manifesto needed to do something for everybody. Under the Conservatives, everybody has seen their economic floor lowered and their safety nets dismantled. The Labour manifesto didn’t attempt to people please, it merely identified social and economic injustices and called them by name. The manifesto set out to empower renters, increase support for pensioners, improve the lives of disabled people, tackle in-work poverty, restore dignity to the NHS and reduce income inequality. These policies set out to roll back the Conservatives’ austerity program and provide a remedy to many of the injustices that plague modern Britain. Many in the country saw the manifesto for what it was, a prescription for Britain’s many ills, not a people-pleasing, everything-to-everyone wish list.
[P1] Labour's manifesto tried to be everything to everyone. [P2] Voters saw through this and turned away from Labour. [P3] Therefore, the Labour manifesto was a key component of their election day defeat.
Rejecting the premises
[Rejecting P2] The voters did not "see through" the manifesto. Many of the policies were highly popular.