At the 2010 Polish presidential election , following the Smolensk air disaster which killed the incumbent Polish president Lech Kaczyński , Tusk decided not to present his candidature , considered an easy possible victory over PiS leader Jarosław Kaczyński . During the PO primary elections , Bronisław Komorowski defeated the Oxford-educated , PiS defector Foreign Minister Radosław Sikorski . At the polls , Komorowski defeated Jarosław Kaczyński , ensuring PO dominance over the current Polish political landscape
Smolensk air disaster
2010 Polish Air Force Tu-154 crash
Civic Platform