 Speaker's Lobby. The path to the majority in the House of Representatives snakes along Interstate 5 from Washington, Oregon, and into California. A dozen races there are competitive. Democrats currently control six of those districts, and Republicans control the other six. If Democrats sweep the vulnerable GOP seats while holding their own, they would exceed the four-seat gain they need for a majority. But the vulnerable Democratic seats give Republicans an opportunity to grow their majority. Look at Washington's third district in the southwest part of the state.