The Parties
Republican:
Economy: Laissez Faire. The government should stay out of the economy. Workers have all the rights they really need. Government pensions and a (very) low minimum wage can be discussed, but any expansion of current reforms is out of the question. The current government funds:expenditure ratio is small enough anyway.
Federal Power: The federal government is the highest authority in the nation. The states gave DC authority over them in perpetuity when they joined the union. That authority however, is only to be used when it is deemed necessary. The government has the right to arrest people who threaten the federal government, such as Vandrove.
Foreign Policy: America is a safe haven of democracy and liberty. It is the duty of the United States to protect that safe haven from external and internal threats at any cost, even if it means war.
New Democrat:
Economy: Interventionist. The government should do what is necessary to protect the national and/or global economy from collapse in extreme circumstances. Otherwise, minor subsidies for struggling industries or corporations are in order. Their stance on workers' rights is similar to the Republican one, but more flexible on government pensions.
Federal Power: Similar to the Republican stance, but less inclined to arrest potential troublemakers.
Foreign Policy: America is not just a haven of liberty, it is its harbinger. It is the American Mission to promote and protect democracy. To complete that mission, the United States should use any means necessary. Even war might be used as a last resort.
Libertarian:
Economic: Heavily Interventionist. Major subsidies. The workers have rights, but not enough of them are protected by law. The Libertarians push for pensions, minimum wages and expansions of current reforms. Stock reform, monopoly-bashing and hard actions on cartels are all on the agenda.
Federal Power: The party is slowly busting at the seams on this. The part of the party that believed in minimal federal involvement has slowly left for the Republicans and New Democrats since the formation of the party, as the Social Unionists and Marxist/National-Vinogradists have completely hijacked the party. This is the party everyone else fears will turn the country into a communist dictatorship. That should give you an idea on their view of federal power. Unfortunately, the remaining three branches of the party can't agree either.
Foreign Policy: First comes revolutionary success in America, then the world.
If you want me to add stances for clarity. Tell me.