Found this free, not sure how long it will last.
Copy/paste from steam description:
About the Game
Sam & Max Episode 4 - Abe Lincoln Must Die - The president's lost it. Federally mandated group hugs, a pudding embargo… what's next, gun control? Sam & Max are off to Washington to take care of this bozo, but the political climate will only get stormier… and a new power will rise…
- One of six self-contained cases with an overarching story arc.
- Simple point & click interface with a low learning curve.
- Catchy jazz soundtrack featuring live performers and over three hours of original music.
- Intuitive gameplay that appeals to new players as well as adventure-game diehards.
- And it's funny!
Sounds like it's permanent. This episode has been free before and is quite old now. It sort of works as a demo for the series.