New research suggests you should consider the timing of your message and what the audience has to do next to decide which approach is best.
A blog post by Bob Sutton discusses recent studies that gauged the effectiveness of political messages:
“The question tackled by these studies in paper by Hakkyun Kim and his colleagues in the Journal of Consumer Research was when ‘influencers’ are better off using vague, abstract high level messages—ones that are more about ‘why’—versus concrete, specific, implementation oriented messages—ones that are ‘how’ to get things done.”
The studies said audiences receive political messages differently depending on when they hear them. Abstract, inspiring language works fine when the election is far off, but as it gets closer, citizens prefer more concrete promises.
The researchers liken it to planning a vacation. Vague promises of sunsets may convince you to travel somewhere at first, but you will likely want to see an activity schedule or something more concrete the week before you depart.