What effect did the shift in population have on American politics?
O
A. As the South's population grew, more people voted for third-party
candidates.
O
B. As the South's population grew, it lost influence in the Electoral
College
O
C. As the South's population grew, so did its effect on presidential
elections.
O
D. As the South's population grew, fewer people voted.

"As the South's population grew, so did its effect on presidential  elections" effected the shift in population on American politics.

Option C

Explanation:

Owing to their consistent support for Democrats in all elective positions the district was alluded to as the Solid South. As a consequence, their Congressmen achieved seniority in many terms, allowing them to control numerous Congressional committees.

Researches indicate that because of social conservatism, Southern whites moved to the Republican Party. Democratic loyalties fell first at the presidential level among white Southerners, accompanied at the local and state level much longer. Thus many campaign resulted shift of population.

the answer to your question is true