Perhaps I am just jaded as an American, but in the US political parties aren't like that. They change their stance according to whoever is the leader of the party.
Political parties in the US tend to band together under a common political view, but they aren't uniform. On the Republican side, you'll have the Neo-Conservatives who are the party of intervention, of projecting American strength abroad and of proactively dealing with threats to the country and its allies. On the other hand, you'll have the Tea Partiers, who are the more Libertarian wing of the party and may have strong disagreements with the USA sending troops and money to other countries. Like Rand Paul, they might even be isolationist in comparison. You'll have the evangelicals who can belong to either camp, though they'll sometimes get a cold welcome from the tea partiers, many of whom won't share in the Dominionist sentiments. The Tea Partiers will be more for privacy rights (against the government), while neo-cons will be more likely to engage in domestic spying.
Yet they almost all agree that most local decisions should be left to local and state agencies rather than the federal government. They almost all will agree that federal taxes are too high, and they'll think that federal spending on social programs should be cut and either moved to the states, be shifted to charity, or eliminated entirely. They'll all tend to be against gun control and abortion, and for strong border security.
Similar factions exist in the Democratic Party, where you'll have the more business-friendly moderates, the more socialism-favoring left, and varying levels of anti-war or interventionism. What seems consistent across the two parties is that with some exceptions, most people can overlook a candidate's position on a single issue if they agree with much of the rest of his platform. A Democrat who is anti-war could still vote for Obama despite his mixed record on that front, an Occupy Wall-Streeter could vote for Hillary even if she's a bit too cozy with business for their tastes. For me, the most frustrating part of trying to find a third-party candidate that I like is that so many of them are single-issue candidates, while the President and Congress have to be adept at a very wide spectrum of issues and policies.