Bloomberg needs to use the next $400 million in ad spending to attack Sanders on his potential weaknesses in a general election and highlight how far left his campaign is. Hitting him on his past record on guns is a must.

Bloomberg also needs to drive home the fact that very little of what Sanders has proposed has any chance of being implemented without serious challenges and major compromises, as even, for example, Rep. Alexandria Ocasio-Cortez admitted on Medicare for All.

Sanders’ praise of Soviet-backed regimes is ripe for political attack ads — and if Bloomberg doesn’t take advantage of this, Trump certainly will in the fall. Finally, Sanders’ legislative record of achievements is lacking, and the difficulty he faces in garnering support among both Democratic or Republican lawmakers can be highlighted.