Political parties, like other organisations, pursue established strategic and operational goals, their primary aim being to maximise election support, but they do not operate in a vacuum; rather, they are surrounded by a range of different environments. Their success rests on their ability to adapt to these environments, which varies across parties due either to difficulties rooted within the parties or to the complexities of their environments. However, many political parties try to take an active approach rather than a reactive one, tailoring and fabricating their various environments to fit themselves rather than the other way around. Our paper focuses on Slovenian parliamentary political parties and their ability to (re/pro)act in relation to various environments—primarily the general public. By applying quantitative text analysis, we utilised party programmes as indicators of adaptation to the beliefs and attitudes of the general population, which was examined by analysing public opinion surveys. The text analysis demonstrated that the political parties are not reactive to the beliefs and attitudes of the general population but rather to expectations coming from the international environment—primarily the European Union.