[8] Rubalcaba's early involvement in politics began in the wake of the murder of fellow Colegio del Pilar alumni Enrique Ruano [es] by the Francoist secret police.

[10] He represented Toledo in Congress from 1993 to 1996, Madrid from 1996 until 2004, Cantabria from 2004 to 2008 and, despite not being Andalusian, was put forward for the safe parliamentary seat of Cádiz in the 2008 election, which he won.

[11][12][13] With Felipe González's election win in 1982, Rubalcaba took on various posts in the Education Ministry, including Director of the Technical Cabinet for the Secretary of State for Universities and Investigation.

It was in this ministry where he gained popularity within his party, thanks, among other measures, to the change of direction in the fight against terrorism that led to the end of the violence of ETA.

However, several media and political parties accused Rubalcaba of being involved in the Faisán case, about an extortion network of ETA, a fact that has not been verified.

[20] After the socialist victory in the general elections of 2008, Pérez Rubalcaba kept his ministerial portfolio, remaining Interior Minister during the IX Legislature.

[22][23] On 21 October 2010 he replaced María Teresa Fernández de la Vega as Deputy Prime Minister and Spokesperson of the Government, combining this with his responsibilities as head of the Interior portfolio.

Nevertheless, in May 2011, Chacón announced that she was withdrawing from the race, and in June Rubalcaba was chosen unopposed as the PSOE's candidate for Prime Minister at the 2011 general election.

[31] He applied to succeed José Luis Rodríguez Zapatero as PSOE's General Secretary and won the vote, held on 6 February 2012.

[45][46] On 3 November 2020, Interior Minister Fernando Grande-Marlaska announced that he would posthumously award Rubalcaba with the police force's highest honours, to commemorate his work against organised crime and terrorism, in particular against ETA during Zapatero's government.