During the last presidential campaign, most true conservatives split their votes between Ted Cruz and Donald Trump. After the primaries, real conservatives, including the Freedom Caucus, pledged their support to Trump.
During the summer, when bad news was coming out about Trump, House Speaker Paul Ryan and Senate Majority Leader Mitch McConnell either turned their backs on Trump or refused to support him. Even as late as October and with more bad news, Ryan refused to endorse Trump. McConnell was quiet. The Freedom Caucus was solidly behind Trump.
When Ryan tried to force through an Obamacare-lite health care bill, the Freedom Caucus worked to change the language to get a bill the House could pass, even as caucus members are being threatened with opposition in the next election. Trump should remember that loyalty is a two-way street.