Libertarianism is basically a fundamentalist version of liberalism. It's essentially "liberalism has gotten too complicated and the complexity is producing errors; here are the most important bits and they're what Really Matter", which is what fundamentalism is.

It's a fundamentalist version of economic liberalism certainly, but not of political liberalism in the sense of vaguely leftist centrism.

Political liberalism is and always has been nonsense. It's a propaganda label and is as meaningful as having a Libertarian Party with a platform half the libertarians in the country disagree (all of whom contend that those who do agree aren't True libertarians).

> By the standards of anywhere else there is only very right / slightly less right.

Depends. Germansy is rather social democratic, but to a German government subsidised housing (via Fannie Mae and Freddie Mac) and universal minumum wage sound vaguely socialist.

And describing Obama/Dems as a liberal when hes/they are centre right.

There's a wonderful short story by Orson Scott Card titled God Plays Fair Once Too Often concerning this.

The Democratic Party is trying to gobble up more of the economy to spend through the federal government, the Republican Party is trying to make it eat less. How are they not left and right?

And under George W. Bush the Republican party created the Department of Homeland Security, the purpose of which is arguably to "gobble up more of the economy to spend through the federal government." And engaged in new excesses of deficit spending (since exceeded by Obama, true).

The broader point is that politics is multidimensional. It's not just one axis. The history of tech policy votes in Congress is a good example that's close to HN home.

You can't map being right and left wing to a scale measured by "desired percentage of GDP to be spent by the government." Consider: Bush or Clinton? Huckabee or Romney? FDR or Hitler? Ukrainian anarchists or Stalin? French monarchists or Jacobins? Southern segregationists or Northern industrialists?