When Brexit and the coronavirus blurred into a political fog engulfing the U.K. last year, at the center of it inevitably stood the leader who has been defined by both.

Prime Minister Boris Johnson stuck to the line that his country was at a turning point, on the cusp of a return to greatness after leaving the European Union. A shortage of critical workers, supply chain disruption and a rollercoaster resurgence of virus infections were bumps in the road on the journey to his much-vaunted "Global Britain.”

As the world confronts the latest incarnation of COVID-19, the U.K. has record infections and is taking another hit to its economy. But for Johnson, Brexit and the pandemic are morphing into a political demon that now risks slipping out of his control after the more radical elements of his party gained the upper hand.