And I want to be clear, in the U.S. Dems are a center-left party and GOP is a (increasingly) far-right party. You can see this objectively by the percent of the time each member flips. Approx. around 80% GOP never flips versus only 20% Dems.

Have you been using Fox news exclusively to form those opinions?

From a British perspective, the Democrats are to the right of all the major parties in our parliament.

There are people who identify as Democrats who could be described as extreme left, and they may get a lot of airtime, but they do not represent the party and do not influence it's policies.

She'll be leading the party in 5 years.

We are either reading very different news, or your use of “extreme left” is highly out of sync with anything approaching common usage. Wake me me up when they start nationalising pensions

They're described like that by the local standards of the country they're in. But if you were to transplant e.g. some "right wing" parties in certain European countries to a country like the US you'd have an extremist left wing party by local standards.

So it's no more evidence that things move towards the "center" in general than people in Venice and Mexico city saying "uphill" and "downhill" being evidence that those two cities are situated at the same altitude.

Fiscally conservative right wing parties in those countries typically run on a platform of at most reducing that by 3-5%.

If you then take what they'd do to military spending (at most 1/2 or 1/4 what the US spends per capita), social services (maybe a bit less spending, but not dismantling it), the state's regulatory role, fuel taxes etc. I don't think this is a far-fetched assertion.