Extensive research has been done on how social media have changed democratic society, politics, and public opinion. Social media are often regarded as a mirror of the public that, during political events, provides journalists and academics with a clear image of what position the public has on political issues and which sub-issues it uses to back it up. Yet, there is strong empirical evidence that active Twitter users differ in terms of background characteristics from the electorate, and that the most influential users possess specific traits. However, this does not necessarily mean that the opinions expressed on Twitter cannot reflect public opinion. This study aims to compare sub-issues used on Twitter to polled public opinion data in the context of the 2016 so-called Ukraine referendum’ in the Netherlands. Our main findings indicate that there is a remarkable resemblance between the two domains in terms of sub-issues used and prominence of these sub-issues. Yet, this is mostly the case when not taking duplicates or retweets into account. Overall, the Twitter debate showed to be less nuanced than the polled public opinion data, as fewer sub-issues appeared.