Patriotism
Historically, advocates of patriotism and nationalism had always been out to victimise vulnerable groups in society. If you disagree with the status quo, then you are a non-conformist and essentially opposed to the nationalist creed. Before you can blink, you are labelled "unpatriotic".
Words like patriotism and nationalism are diametrically opposed to words like "dissent" and "non-conformity". I am not asking that the latter duo be made the mainstay of national debate (that would be missing the point entirely). My point is that those espousing patriotic fervour usually succeed in criminalising dissent. This should never be allowed to happen in a liberal democracy.