Patriotism is seldom a problem. “Anti-patriotism” in the guise of internationalism is always a problem, because, in effect, embracing internationalism is embracing treason.
The Socialist International is an organization composed of leftist political parties around the world. The US Democrat party is a “de facto” member, if not a “de jure” (open) member.
And one of their strongest precepts is that nations have no reason to exist, should cease to exist, and be replaced with socialist districts in large economic blocs under a one world government.
Therefore, nobody associated with them and their ideas can legitimately claim to be patriotic, because they are anti-patriotic. In political office they seek to undermine their nation’s unique culture, homogeneity, people, history, and language with open borders and unlimited immigration.
They seek the destruction of their nation. As such they are a tangible threat, not a hypothetical threat of someone who is “too” patriotic.