Because they started liberalism..
.. Inspired by Europeans like:
(Baron de Montesquieu)
They call them ‘ classical liberals ‘.
In The Netherlands, we still got liberal people like Thorbecke:
(Thorbecke, where we owe our parliamentary democracy)
All liberals, children of the Enlightenment, who came with enlightened ideas such as: King (and actually nobody) must have the absolute power; The law applies to all; Separation from church and state.
Good ideas where the American Founding Fathers based their declaration of independence and following the Constitution.
And then came Reagan and Francis Fukuyama.
(Francis Fukuyama, American thinker and founder of the neo-conservative movement)
Ideas from the Enlightenment were suddenly scary-leftist ideas.
Corporatism became a much more important guideline. Something we call neoliberalism. The (incorrect) thought that thinkers like Adam Smith and John Maynard Keynes had actually opposite ideas. In Reality, Smith’s trading spirit was deadly to freedom, and Keynes invented industrial monopochemical freedoms. However, both were free, liberal economies. But for Americans, one is a ‘ classic ‘ (good) liberal, and the other a left-wing socialist. Because the one they have actually forgotten, and the other is in the way of corporatism and must be a the supporter of Marx and Engels.
They are not really opposed.Many European liberals would choose the side of the American Liberals in America and vice versa -especially when it comes to personal freedoms.
Originally liberalism was a left-wing movement, which wanted to reduce the power of the nobility and the church.In America it led to American independence, whereupon liberalism remained there always left. In Europe, the Socialists are split on the left side of the Liberals, so the Liberals remained more or less in the middle. Here Liberals often work together with conservatives to save won freedoms from socialism.
The United States has long been a two-party system, which makes the development of independent political parties less opportune.A successful Liberal party would vote in favour of the Democrats, after which the Republicans would win all the elections in future. Proportional representation here has the opposite effect. Socialist and conservative parties often need help to reach a majority and liberals are strategically positioned in the middle to help the most liberal of those two.
Both have developed their own political development and can grow meanings of words ‘ apart ‘.For comparison ‘ a weird coin ‘ is not the same as ‘ a rare coin ‘.