[citation needed] Under Slobodan Milošević and the Socialist Party of Serbia, he and Šešelj were sentenced to three months in prison which he served in Gnjilane.

He then ran in the 2003 Serbian presidential election, in which garnered the most votes in the first round (46.23%), ahead of Dragoljub Mićunović, but the results were invalidated due to a low turnout of only 38.8%.

In contrast to Đinđić, Nikolić repeatedly refused to apologise for stating "I don't regret that Slavko Ćuruvija was murdered".

[17] On 9 May, Nikolić met with Russian Ambassador Aleksandr Alekseyev and gave a speech to Parliament in which he advocated making Serbia part of a Belarus-Russia superstate, saying that together they would "stand up against the hegemony of America and the European Union".

[21] In the following days, Nikolić formed a parliamentary group with a number of other Radical Party representatives called "Napred Srbijo" (Forward, Serbia).

He also called upon all SRS members to remain loyal to the ideology of "Serbian nationalism, anti-globalism and pro-Russian politics".

[28] On 5 February 2011, in front of the National Assembly, Nikolić and his political supporters – Milanka Karić (Strength of Serbia Movement), Velimir Ilić (New Serbia), Aleksandar Vulin (Movement of Socialists) and Aleksandar Vučić organised a protest demanding early parliamentary elections.

He stated that his goal was to force the then-Serbian government (led by Boris Tadić) to hold early parliamentary elections.

During the campaign, the issue of his education was raised, as the opposition claimed that Nikolić obtained his master's degree under dubious circumstances in a private school.

Nikolić responded by suing the daily newspapers Blic and Kurir, demanding 4 million euros as compensation.

Boris Tadić, his rival in the elections, congratulated him on the victory, and stated that he hoped that Serbia would continue its progress under Nikolić.

[38] However, Michael Martens, a journalist at Frankfurter Allgemeine Zeitung subsequently published the audio recording showing that Nikolić had indeed made that statement.

Štefan Füle, the European Commissioner for Neighbourhood and Enlargement, was the highest-ranking official to attend and many ambassadors from other countries were also present.

The leaders of Croatia, Bosnia and Herzegovina, Slovenia and Macedonia, boycotted the inauguration due to his denial of the genocide in Srebrenica and claims about Vukovar.

[43][44][45] Nikolić's advisors were Marko Đurić, Stanislava Pak, Oliver Antić, Milorad Simić, Radoslav Pavlović, Predrag Mikić and Jasmina Mitrović Marić.

He elaborated "the denial of genocide in Srebrenica will not pave the way for co-operation and reconciliation in the region, but on the contrary, may cause fresh misunderstandings and tensions.

"[47] Catherine Ashton, High Representative of the Union for Foreign Affairs and Security Policy, condemned his comments and stated that "the EU strongly rejects any intention to rewrite history.

[48][51] As President, Nikolić has decorated a large number of domestic and foreign individuals and institutions on the occasion of Statehood Day.

[54] In February 2017, Nikolić announced that he would not seek re-election in Serbia's forthcoming elections and extended his support to Aleksandar Vučić.

[56][57] Nikolić told Večernje novosti in 2004 that the boundaries of Greater Serbia along the Virovitica-Karlovac-Karlobag line were not part of any imperialistic politics, but would always remain a "dream" for him and other Radical leaders.

[60] But a few days before the 2012 elections, Nikolić told the Frankfurter Allgemeine Zeitung in an interview that the territorial integrity of neighbouring countries cannot be questioned and that his former opinions were no longer valid.

[63] In 2012, Nikolić was accused of buying a master's degree from the Faculty of Management in Novi Sad without attending a single class or exam.

[64][65] On 25 January 2016, Nikolić laid the cornerstone for "the Centre of Excellence" of the University of Kragujevac, his hometown; the institution will include a stem cell research unit.

The League of Social Democrats of Vojvodina (LSV) also reacted, saying that the president made "a Nazi statement" that "violated the Constitution," and urged him to resign.

[68] Maja Sedlarević, member of League of Social Democrats of Vojvodina (LSV), said Nikolić had offended women and also he is ignorant, uneducated and superficial.