PARIS — Last Wednesday, as the world sought to absorb the news of Donald J. Trump’s electoral triumph, France’s far-right leader Marine Le Pen was up early, already commenting on Twitter. Even before the American president-elect gave his victory speech, she rushed to congratulate him and “the free American people.” This was hardly surprising, since Ms. Le Pen, the leader of the National Front, is hoping to become the next French president.

On Wednesday evening, we watched her holding forth on mainstream television news, where she has not been a regular guest. Most journalists have as little sympathy for her as she has for them, and she had been staying out of the public eye over the past 10 months, working hard to build an electoral strategy. During the period between France’s regional elections last December, when her party scored 27 percent of the popular vote but failed to win control of any region, and the presidential election next spring, she has set herself a single goal: to build enough respectability to shatter the so-called republican front through which mainstream parties unite in the second round of a French election to prevent the National Front from winning.

Ms. Le Pen, 48, has worked patiently to transform her party from a marginal extremist movement into an organization able to seize and exercise power. Now she needs to ramp up the frustration among French citizens, which has already propelled her to the top of opinion polls ahead of the first round of presidential voting on April 23, into a force powerful enough to break the barrier of conventional politics and push her through to victory in the second round, scheduled for May 7.

She is emboldened by Mr. Trump’s upset of Hillary Clinton, which she thinks has significantly enhanced her chances of achieving just that. What the president-elect has done, she said on French public television, has been to “prove that what was presented as impossible can be made possible.” Now she confidently says she believes that it can also happen here — that France in 2017 will provide the third stage of a global political uprising begun by Brexit and reinforced by Mr. Trump’s victory.