[4] Esquerdo unsuccessfully ran as a candidate for the Congress of Deputies in the February 1891 general election, the first one since the restoration of universal male suffrage in Spain.

[6] Esquerdo ran again as a candidate for Madrid to the Congress of Deputies as part of a joint Republican ticket named "Unión Republicana" at the 1893 general election.

[8] The party thus lost the newspaper's support and was forced to replace it with the newly-created El Progreso in 1897, edited by Alejandro Lerroux.

[8] Esquerdo vied as the Republican–Socialist Conjunction (CRS) candidate for Madrid at the 1910 general election and again earned a seat at the Congress of Deputies.

[9] He participated in the Central Committee of the CRS meetings, where he grew closer to the faction favoring collaboration with the government, which was represented by Melquíades Álvarez and Gumersindo de Azcárate.