I’ve heard that said many times. I don’t believe the Congress would have declared independence with that low support. I think the Tories were maybe 10% tops. Very few joined the Tory militias and very few left to Canada after the war.
Thank God for Ben Franklin and his abilities with the French. Of Course, Thank God for a lot of others as well.
However, the Brits did come back eventually and they were still pissed.
Many of the Tory “supporters” were people whose livelihood was dependent on Tory occupation, so their “support” was not ideological.
Therefore they were uninterested in fighting a war to defend the Tories.