What are the current political parties’ ideas about government?

The Democratic Party's philosophy of modern liberalism blends notions of civil liberty and social equality with support for a mixed economy.[20] In Congress, the party has influential centrist, progressive, and conservative wings. Corporate governance reform, environmental protection, support for organized labor, maintenance and expansion of social programs, affordable college tuition, universal health care, equal opportunity, and consumer protection form the core of the party's economic agenda.[] On social issues, it advocates campaign finance reform,[] LGBT rights,] criminal justice and immigration reform,[ stricter gun laws,[] abortion right] and the legalization of marijuana.[]

The 21st-century Republican Party ideology is American conservatism, which incorporates both economic policies and social values. The GOP supports lower taxes, free market capitalism, restrictions on immigration, increased military spending, gun rights, restrictions on abortion, deregulation and restrictions on labor unions.[] After the Supreme Court's 1973 decision in Roe v. Wade, the Republican Party opposed abortion in its party platform and grew its support among evangelicals.[] The GOP was strongly committed to protectionism and tariffs at its founding but grew more supportive of free trade in the 20th century.

Explanation:

after the roman empire, the catholic church began to unify by taking on many duties of a government.