This method divides electoral votes by district, allocating one vote to each district and using the remaining two as a bonus for the statewide popular vote winner.
Using Congressional districts to determine each elector would also draw more attention to the way districts are drawn, already a hot-topic in politics today.
Cons:
The vast majority of districts are drawn as “safe zones” for one of the two major political parties. For this reason, basing electoral vote allocation on Congressional districts as well would raise the stakes of redistricting considerably and make gerrymandering even more tempting.
Also, while the current system causes the candidates to pay the most attention to just a handful of states, the Congressional District method would actually make their attention even more tunneled.
Candidates would rather shift their focuses to competitive districts, the number of which would be small enough to further reduce the reach of presidential campaigns, promises and attention.