She began her career in Grupo Sophia, a think tank founded by Horacio Rodríguez Larreta. She was named director of the group's social policy desk in 2000, as well as of Fundación Creer y Crecer, a think tank organized by Commitment to Change, a conservative political party led by mayoral candidate Mauricio Macri.[8] She is also a member of Washington D.C. based think tank, The Inter-American Dialogue.[9] Vidal was elected to the Buenos Aires City Legislature in 2003, and was appointed Chair of the Committee on Women and Youth.[7] She served in the Human Resources Department at PAMI (the national health insurance service for the elderly and disabled), and as adviser to ANSES (the social security administration), as well as the nation's Ministries of Social Development and Foreign Relations.[10][11]
Vidal's profile rose following the 2009 election of Deputy Mayor Gabriela Michetti to a seat in the Chamber of Deputies, and she became Mayor Macri's most visible female adviser.[1]
Following Macri's decision to forfeit a PRO candidacy for the 2011 presidential election, and instead seek a second term as mayor, he nominated Vidal as his running mate.[10] The duo were reelected by a landslide on July 31, 2011, receiving over 64% of the vote with sociologistDaniel Filmus coming in 2nd place.[13]
Macri selected Vidal as the candidate of his party to run for governor of the Buenos Aires Province in the 2015 elections. The Radical Civic Union, allied with PRO in the coalition Cambiemos, proposed to replace her with Ángel Posse, but Macri kept Vidal. In another negotiation it was proposed that Sergio Massa resigned as candidate to the presidency and ran for governor in Macri's ticket, but Macri kept Vidal as candidate again. She was the first female governor of the province, and it is the first time in 28 years that a non-Peronist candidate has won the election in the country's most populous province.[14]
On 10 December 2015, she swore before the Buenos Aires Legislature.
Shortly after assuming as governor, she announced that she would live together with her husband, Ramiro Tagliaferro, in a special residence within the perimeter of the Morón military air base. Although she later divorced Tagliaferro, she continued to reside in the residence for security reasons after having been subject to police threats.
In April 2018, the Konex Foundation awarded her a Konex Award – Diploma of Merit in the Public Administrators category.
The Spanish newspaper El País named her "the Argentine Thatcher" after Vidal's intense confrontations with Peronistunionists during her mandate.[20]
After the disappearance of Cecilia Strzyzowksi in 2023 she said "we demand that the provincial justice system act quickly, without delays, without ifs and buts and without attempts at a cover-up. The political ties of the accused cannot interfere. Impunity is not an option".[21]