Elizabeth Warren set the tone for the party’s progressive wing, but others among the 10 candidates were more cautious, producing clashes along ideological lines.
The Republican-controlled Senate rejected a House border bill that reined in Trump immigration policies, then passed its own version with few strings attached.
House Democrats pushed through $4.5 billion in humanitarian aid to address the plight of migrants at the southern border, after leaders quelled a revolt.
The New Jersey senator is a gifted orator with a glittering résumé, but he often pulls back from political infighting. The debates offer him a chance to break out.