Democratic frustrations with the House majority’s oversight of President Trump are beginning to boil over, as longtime party strategists and liberals alike decry what they view as an ineffective effort to hold a lawless president accountable.

In more than seven months of investigating Trump, a half-dozen Democratic-led House committees have struggled to unearth major findings, hold high-profile hearings that move public sentiment or follow up on inquiries they laid out when the party took the majority in January.

The thin record increases the pressure on Democrats for Wednesday’s hearings with a long-sought witness, former special counsel Robert S. Mueller III, who will answer questions about his nearly two-year investigation into Russian interference in the 2016 election and whether Trump tried to derail the inquiry.