“The whole state must be so well organized that every Whig can be brought to the polls. So divide the country into small districts and appoint in each a committee.
Make a perfect list of the voters and ascertain with certainty for whom they will vote.
Keep a constant watch on the doubtful voters and have them talked to by those in whom they have the most confidence.
On Election Day, see that every Whig is brought to the polls.”

- Abraham Lincoln, first Republican President

Substitute ‘Republican’ for ‘Whig’ in the above, and this is still a good description of the role of a PCP.

(Lincoln was a Whig before the Republican party existed. The Whig party tore itself apart over the slavery issue.)