Over the past fifty years, many Americans have moved from the Northeast and the Midwest to the South and West. As a result of this population shift, the South and West have gained influence in

House of Representatives

Explanation:

This is a question relating to the U.S. Legislature.

As a result of the Great Compromise of 1787, the U.S. has two Houses in Congress. The Senate has equal representation for all states and the House of Representatives is based on the population in the states.

With many Americans moving to the South and West, the population of those areas will increase which will translate to them getting more seats in the House of Representatives which as just mentioned, is decided by population.