Minority Leader Nancy Pelosi spoke on the House floor for eight hours Wednesday, giving the longest speech in that chamber in at least a century. She did so to pressure Speaker Paul D. Ryan to permit a vote on protecting the roughly 700,000 undocumented “dreamers.” Republicans expressed delight that eyes were on the polarizing Pelosi, but her marathon speech served to energize activists while highlighting that House Republicans will not commit to a vote. Despite having little leverage, she scored a tactical success. It’s not just Republicans who discount Pelosi’s talents. Some Democrats are unsatisfied with her leadership: They accuse...