IMO RINO's are Democrats, who infiltrated the Republican party.
Well, there are definitely infiltrators but there are also old guard elitists such as Lincoln and Reagan had to deal with, who put their businesses ahead of the country.
But then, Reagan was a former Democrat - infiltrator - from the Democratic Party, too. As is Trump. But Reagan at least wasn’t a narcissist and had the sense to make the economy a major issue rather than himself.