If re-unification is an internal issue, even 100% US citizens support Taiwan independence, it is still useless. The support has to be from the involved parties, not external parties.

To give an example, China cannot have a voting power on whether Hawaii or Alaska should be an independent country. Not even peoples in Hawaii or Alaska. It has to be votes from all US citizens, not just votes from Alaska or Hawaii either.

In the US Civil War, 99.9% of Southerners are pro-independence. But >50% of Yankees are against it. So the Civil War started. From that example, we can see, even if 99.9% of Taiwanese are pro-independency, it is not going to work, so long >50% of mainland Chinese is against that.

That is the reality. Don't cheat on yourself. If Taiwan really wants independence, you have to find a war, and have to win it. You have to fight until >50% of mainland Chinese are not against the independence of Taiwan.

Peacefully accepting the unification, or get ready to fight. No other choice (there was a third choice, to keep the status quo, but Chen ShuiBian chooses to not take that).