Thatcherism inverted the political polarity so the radical Right became the radical force

Evidence

It is the Labour Party which is committed to things as they are—and Mrs. Thatcher who means to tear society up by the roots and radically reconstruct it! This is the process by which—as they say—the radical Right has “become popular.” — Hall, Stuart, Essential Essays, Volume 1, 1121

Categorization

• XREF: Central to the reader’s purpose: the mechanism by which the Right captured the mantle of radical change, against the left’s defense of the status quo. — connects to: Left-wing radicalization, not right-wing opposition, made Labour unelectable for two decades — Philip Mirowski & Dieter Plehwe (eds.), The Road from Mont Pèlerin: The Making…, 424
• SEED: Angle for an essay: how parties of change get reframed as defenders of the status quo, and the tactical lesson for would-be reformers.