The continued investigations and seemingly unhinged behavior with all things Trump is doing them no favors. Only their hardcore base is encouraged by it. They should have stuck with the Russia investigation and Mueller report and continued to pound that (regardless of what people perceive was in the report). The fact that they have all but dropped the Russia collusion in favor of the issue du juor undermines the credibility of the original claim.
Instead, they have jumped from scandal to scandal and end up dropping each one after the news cycle tires of the story. The original complaint about Trump is weakened with each new issue that goes nowhere. Spoiler Alert: This latest scandal isn’t going anywhere either. Actual articles of impeachment would only compound their problems.
The Dems will go into 2020 having accomplished nothing from a legislative perspective and Trump will crucify them for it. They’ve squandered two years of congressional control and it looks bad. While they’re at it, they have likely screwed any chance Biden had of being elected. Warren is unelectable.
IMO, they should have spent the last three years making the case for themselves rather than making a case against Trump.