A big part of the Party's legitimacy is that they succeeded where the Nationalists failed: They kicked out foreigner powers from China and reasserted Chinese sovereignty.
Getting HK back is a major achievement for them with the full support of the Chinese public (even for people sympathetic with HK's struggle to maintain its democratic rights).
I think this is something overlooked in the West, if not purposely ignored, with Western media continuously trying to paint an image of China vs HK. HK is a Chinese city within China, inhabited by Chinese people. It just happens to have a special administrative status. The issue is the issue of democracy in China, and whatever will happen to that will be achieved by the Chinese people themselves (see Taiwan), not by foreigners with ulterior motives.
I'm saying this in general, not specifically about the democracy movement but about depiction in the media. In the media HK is almost always presented as "HK v China" like it's somehow a different country. This is an obvious rhetorical trick, IMHO.
Now, regarding those protests, when demonstrators are filmed waving the HK colonial flag, the Union Jack, or the Star spangled banner they are handing a big stick to the central government to label them secessionists and puppets of foreign influence.
Edit: Right now on the BBC there is an article titled "HK's year under China's controversial law", which makes it sound like HK is being occupied by a foreign country...
Getting HK back is a major achievement for them with the full support of the Chinese public (even for people sympathetic with HK's struggle to maintain its democratic rights).
I think this is something overlooked in the West, if not purposely ignored, with Western media continuously trying to paint an image of China vs HK. HK is a Chinese city within China, inhabited by Chinese people. It just happens to have a special administrative status. The issue is the issue of democracy in China, and whatever will happen to that will be achieved by the Chinese people themselves (see Taiwan), not by foreigners with ulterior motives.