You need a real time voter database.
A database of every eligible voter that tracks their real time behavior so you can target ads.
Get your vote totals you need in each congressional district and state.
Next go through your voter database. Start with most likely to vote for you and work your way to least likely based on budget. You need a weighted voter score that takes into account propensity, uplift, electoral college impact, and marginal votes gained from social network
Don't have a real time voter database?
How to build your own