In the short term, it’s President Emmanuel Macron’s government that might take the hit. In recent days National Rally heavyweights have been threatening to collapse it, ostensibly over energy policy. Loyalists close to Le Pen may be tempted now to follow through with those threats. 

The government, led by centrist Prime Minister François Bayrou, has a fragile grip on power.

The far-right party could table a motion of no confidence over energy policy, which could be successful if other opposition parties ― it would need the left to join in ― decide to vote in favor. The National Rally has held back from toppling the government since Bayrou was appointed in December.

Le Pen, who left the courthouse before her verdict was delivered, may decide to take a page from the playbook of U.S. President Donald Trump, who campaigned against legal proceedings launched against him.

She could portray the decision as a left-wing political vendetta and try to galvanize her supporters to campaign against the political establishment. In doing so she’d be echoing remarks made by Trump ally Elon Musk on Monday, who said that “when the radical left can’t win via democratic vote, they abuse the legal system to jail their opponents.”

While Marine Le Pen is likely to resist calling for violence personally, the verdict could fuel resentment in a country whose voters are already frustrated with how things are run. | Benoit Peyrucq/AFP via Getty Images

Although the party has its roots in extreme-right racism and antisemitism, Le Pen has fought to normalize it and widen her electoral base. She has always said she would strive to uphold the institutions of the French Republic, but Monday’s bombshell changes everything.