The RCC should stay out of politics with the exception of working for the freedom to attend one's church of choice. Church/State entanglement is taboo in my book.

Then the RCC should 1) preach a non-politically-aligned message and 2) institutionally serve as an example of that message in action. As the song goes "They will know we are Christians by our love ... " 

If the message and example are accepted then membership in the RCC rises and the politicos, as a matter of practicality, will take notice.

If the message and example does not draw congregants and increase membership then the RCC is doing something dreadfully wrong, or the RCC is greatly mistrusted, most likely due to past actions not yet forgotten nor forgiven.