Kubera was a potential candidate in the 2018 presidential election,[1][2] gathering enough support from fellow senators to register his candidacy, before deciding not to run.

[6] As mayor, Kubera received media attention for his measures to address crime and his attempts to regulate prostitution.

[7] Kubera led ODS to victory for the last time in the 2018 municipal election, and subsequently negotiated a coalition with ANO 2011, before stepping down as mayor to be succeeded by his colleague Hynek Hanza.

Although ODS suffered heavy losses during the 2012 Senate and regional elections in North Bohemia, Kubera received 40.5% of votes and advanced to the second round with Jaroslav Dubský, who had 18.5%.

When asked about Jiří Drahoš, he said that "there are many renowned scientists, but being a president is a political office even though some people might not realise that.

The President should care about the Czech Republic, which doesn't mean he should not be in touch with foreign countries, but the focus of his activities should be here at home".

Political scientists such as Jan Gruber and Lukáš Jelínek viewed Kubera's chances as low, and considered Václav Hampl to be the frontrunner.

[37] On 1 January 2019 Kubera gave his first new year speech as the President of the Senate, warning about the loss of personal freedoms and criticising excessive regulations.

He criticised the influence of social networks and the green wave, and expressed fears that freedom of speech was under threat.

[47] On 14 January 2020 Kubera met with Czech president Miloš Zeman and Speaker of the Chamber of Deputies Radek Vondráček for lunch, and defended his planned visit to Taiwan.

Kubera died unexpectedly on 20 January before his trip could take place, but the letter, written in Czech, "reveals how explicit Beijing was about the possible consequences if the visit had gone ahead.

"[49] Kubera's family accused the Chinese Embassy of sending him threatening letters in the time leading up to his death.

[53] His relatives alleged a threatening message from the Chinese embassy played a part in his sudden death.

[55] Czech president Miloš Zeman expressed regret for his death, saying he considered him as a friend whom he liked despite their differences.

[57] ODS leader Petr Fiala expressed great grief, stating that it was unbelievable, as Kubera had been energetic at the party's Congress.

[58] Former Czech Prime Minister Mirek Topolánek expressed shock, noting that Kubera had seemed to him an immortal, unstoppable, and never-ending individual.

[63] Kubera's unrealised plan was put in action by Miloš Vystrčil, his successor as President of the Senate, when he led a 89-member Czech delegation to visit Taiwan on 30 August 2020.

[64] Kuberová had originally been scheduled to be part of the delegation, but withdrew for health reasons and instead thanked President of the Republic of China Tsai Ing-wen in a pre-recorded video clip.

He argued that member states should have more power than the Union, and was also a critic of Angela Merkel's immigration policy.

In 2017, Kubera appeared in a cameo role as Edvard Beneš in the historical dramatic film Toman.