Considered a hero by the party's supporters, he was adopted as a parliamentary candidate by the MSI soon afterwards and elected to the Chamber of Deputies, representing Perugia.

Although the UDNR's main political goal was the establishment of a secular, democratic "new Republic" with a strong executive branch, akin to what had been achieved by Charles De Gaulle in France a few years before, it also attracted the attention of fascists such as De Felice; this was partly due to Pacciardi's hostility to communism and his desire to overcome "the antithesis between fascism and antifascism", but it also stemmed from the party's rhetorical promises to "remake the state" through strong leadership, which was redolent of mussolinismo.

He was allegedly involved with Ordine Nuovo, engaging in clandestine activity with several Ordinovisti (as a member of the so-called "Tivoli Group") even after the organisation was forcibly dissolved by the government in 1973.

[5] Within that organisation he was, alongside Aldo Semerari, the leader of a "traditionalist" faction that eschewed direct revolutionary action in favour of constructing a logistical base that would bring together like-minded militant groups and individuals, including criminal elements.

[6] De Felice and Semerari were among those arrested in the "blitz" of 28 August 1980, following the Bologna massacre earlier that month in which 85 people died.