That's the curse of big-tent parties. They really aren't good at adapting their platform to fit the "outer" groups, and tend to stick with whatever the hardcore center deem important. This often drives the moderates to the other party (due to the "well, both of these are pretty far from what I want, but THIS group isn't quite as far), and can also drive their supporters into jumping ship or not participating if the "I agree with 90% of what this party stands for, but this bit is something that I just can't be a part of."
The national parties wouldn't even have to change positions on a lot of these issues - just declare that "we recognize that people in different areas have different opinions on these matters, and we feel that this is an issue that is best left to the state branches." There would still be issues in the Presidential elections, where the national party has to take the lead in developing a platform, but things would go a lot smoother at the state level, and lead to a better representation of the popular will there.
Ohio's a pretty good example - both parties would gain a significant boost by dropping a single issue. No matter how red it gets, Ohio is a very pro-union state - the one time the Ohio GOP managed to push through a Right To Work Law, it was thrown out by one of the most lopsided popular votes in state history. Nonetheless, Ohio's cities are solidly blue - largely due to union voters trying to protect their bargaining rights. It is very likely that Mike DeWine would not have won the election if he had not publicly stated "there will be no right-to-work law under my administration." Making "protecting the unions" part of the GOP platform, or even just dropping all anti-union aspects, would probably swing the scales in the GOP's favor.
On the other side of the aisle, gun control is a very unpopular position to take in Ohio, even in the otherwise blue cities*. One of the reasons Cordray won the primary to run for governor is that he didn't support an assault weapons ban, while his closest opponent did. Polling data suggests that a major factor in his loss is that he was essentially forced to align closer to the Party stance on this matter. Just dropping those sections from the state-level party platform would probably bring in a lot of support.
*Toledo's mayor recently put a policy into place that the city would only buy guns and ammunition from "ethical" companies that refused to sell "assault weapons" to civilians, and encouraged other cities to do the same - openly stating that he hoped the loss of government contracts would do what regulators refused to do. Polling data after this move is sparse, but I've already seen at least two people that campaigned for him talking about a recall because of it.