Lacking a particular state to focus on, she should be focusing on her main obstacle: Bernie Sanders. They are competing for progressive populist voters, and he’s the one winning.
She has been loath to accept this political reality. The only person running she feels comfortable frontally attacking on a regular basis is Bloomberg, for trying to win the election through astronomic spending. Warren will attack others on similar grounds—she skewered Buttigieg for his high-dollar fundraiser in a “wine cave”—as it fits her persona as a crusader against Big Money and excessive wealth concentration. But unless she convinces more left-wing voters that she is the superior vehicle for their aspirations, Sanders will be the one carrying the left-wing banner into the Democratic National Convention.
Warren’s attempt to sideline Sanders has been to argue she can best unite the various strands of the Democratic Party, implicitly suggesting Sanders’ appeal is too narrow. That argument hasn’t flown because many on her left don’t care about uniting with the moderates, and those on her right see her as Sanders’ equal in polarization and unelectability. (Warren has also tried to emphasize her gender, but as Klobuchar has risen, that no longer distinguishes her from the men in the top tier.)