I think Jregg actually came up with a generally correct way to look at it, as an amalgam of spectrums that people can differentiate across on different general categories, with the left being progressive, the right being regressive, and the center representing a status quo stance.

I’d say which issues you line up differs from country to country, but for the US for example it’d be something like

Healthcare, Abortion, Welfare, Firearms, Government Structure, The balance between states and the federal government, voting reform, and the role of American Christianity in the government.