Is there any recourse should Congress protect President from impeachment and removal from office despite solid grounds for such actions?
US voters have an opportunity to replace their House Representative every 24 months.
If enough people in a district don't like what their representative is or isn't doing, they can elect a new one.
This pressure from the people is what turned the House Reps against Nixon in 1974. Only when it became clear that the people would not support a Congress that supported Nixon did the impeachment process begin.