[DiogenesLamp]

Of course Lincoln could,

But not lawfully. The constitution isn't flexible. It's rigid.

[Bull Snipe]

The Constitution is rigid. The interpretation of what is written in the Constitution is flexible.

[BroJoeK]

DiogenesLamp: "But not lawfully.
The constitution isn't flexible.
It's rigid. "

Certainly, it "rigidly" enumerates powers:

"To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions;"

Really, you should read it sometime, along with the Declaration of Independence.