The Thoughts Within
The quick answer is by dividing your opponent.
With the US elections a year or more away, the fight is on between the larger democratic base and the smaller (by numbers) republican base. I won’t delve into US partisan population data but instead talk about how the republicans effectively use their smaller base to win elections on a national scale. Part of that has to do with getting more people out to vote but a significant part of the campaign is dedicated to getting democrats to abstain.