The Republicans, as a party, have no message at all. They coasted on tax cuts since 1984, but that message was neutralized by the Democrats when Obama opted to keep all the Bush tax cuts in place except for the top bracket. Republicans have never quite processed this, so now they just kind of flail. What they don't understand is that on its most basic level, winning an election is driven by addressing some core anxiety of voters and by turning out your voters. Unfortunately, the party is infested with people who think addressing a voter anxiety is "socialism." They're also full of idiots who think our biggest problem is being accused of racism, so they make proving how not-racist and not-sexist they are a top priority.
A very stark example is that a huge problem in Los Angeles is a literal rat plague, and Republicans still have not hit on the idea of running on a platform of fixing the city's "piles of rat-infested garbage" problem.