The parallel displays by two of the three leading Democratic candidates offered a possible preview of the collision course looming if Biden and Warren maintain their current trajectory. It would be a clash of opposites: the progressive firebrand against the establishment favorite; the cerebral candidate of big, bold plans vs. the elder statesman offering himself as a safe haven for people who simply want a return to pre-Trump normalcy.

With Warren rising in the polls and Biden’s lead narrowing since late spring, her message is igniting progressives…

But while Biden, for now, has the centrist, establishment path largely to himself, Warren still has Bernie Sanders in her progressive lane. Sanders has an even bigger small-dollar army, and also drew big crowds this week in Sacramento, Calif. and Louisville, Ky. The two are projecting similar messages, railing against the ultra-wealthy, asking people to join a broader movement, and subtly hitting Biden by warning against incrementalism.

Sanders isn’t viewed by Biden’s campaign as having as much room to grow as Warren. But Biden’s camp does see the continued strength of both Warren and Sanders as an advantage, each limiting the other’s ability to expand their base of support. Sanders’ campaign thinks he can eat into Biden’s support because of demographic overlap between their voters.