Your best bet is to claim yourself Independent.
And then decide on each policy or candidate on their own merits.
In the end, both parties are out for their own,
so vote with your heart, and not on the line.
BTW...don't let anyone tell you that you "have to" belong to a party,
being Independent is what being an American is all about.
P.S.
Republican - lower taxes, military/industrial support, moral programming, individual rights
Democrat - Union/Agricultural support, governmental programming, civil rights
Libertarian - lower govt, lower taxes, lower subsidies (no real civil stance), individual rights
Green - Environmental, Anti-industry (no real economic policy), civil rights
(**this is just overall rhetoric platforms...but many times it blends together)
This is all domestic agendas
With foreign agendas they all go back and forth with whether we should get involved or not.
It depends on the cause.
Both Dems & Reps claim to be for being in budget, neither is able to stop spending money.
Neither Libertarian nor Green has enough backing to get consistent or strong representation.