Born to a Swiss father and a Peruvian mother, Mulder attended the Pontifical Catholic University of Peru in Lima, earning his law degree in 1979.

Due to Jorge del Castillo's appointment as Alan García's first prime minister of his second presidency, Mulder held both institutional and political affairs until he stepped down in 2010.

In his tenure, he overtook a strong role in the Supervision and Comptrollership Committee, serving as a fierce leader of the opposition caucus against Alejandro Toledo's administration.

The final report was submitted to the Truth and Reconciliation Commission, alleging human rights violations, illicit enrichment, electoral fraud, among other charges.

[1] Alongside Jorge Del Castillo, Mulder served as one of Alan García's main congressional leaders for the upcoming 2006 general election.

García ultimately won the presidency, and appointed Del Castillo as Prime Minister of Peru, while Mulder assumed both offices of secretary general, and was reelected to Congress simultaneously.

According to Mulder, the bill aimed at the "waste of resources" after seeing an advertisement with the slogan "SUNEDU is like that brave aunt who defends us" and that "there are means that live off what the mayor or the governor transfers to them".

[14] Likewise, on June 20, 2018, the Peruvians for Change caucus filed an opposition lawsuit signed by 33 members of Congress from Popular Action, Broad Front and Alliance for Progress.

[18] On September 30, 2019, president Martín Vizcarra proceeded to constitutionally dissolve Congress following the factual denial of confidence of his cabinet led by Salvador del Solar.

His remarks were widely dismissed by pundits, viewing the end of his political career due to the perception as one of the most unpopular politicians of the term.

He was harshly criticized within his party, specially by his former colleague Jorge del Castillo, who expressed his disconformity with the primaries to which Mulder was to be subjected to.

The party's institutional secretary general, Elías Rodríguez claimed that Mulder was an invited candidate rather than an elected one in the primaries, as he was assigned the number 1 in the list for the Lima constituency.

The controversy rose when it was revealed that Mulder's name was in the ballot for the primary election, spreading rumors that he obtained a low share of votes, and concluding that he would be in the list by invitation rather than a formal nomination conducted democratically.

[20] Mulder himself denied the allegations, claiming that Del Castillo opposed his candidacy for past differences while serving in Congress, declaring his relationship to be of rivals.

[21] The exit polls gave the Peruvian Aprista Party 2.7% of the popular vote, thus failing to pass the electoral threshold, and preventing Mulder from returning to Congress.