Why Has Campaign Spending Increased in the United States

Why has campaign spending increased in the United States?

A) Eliminating restrictions on campaign contributions has made it easier for candidates to raise more money.
B) The shift from television advertising to labor-intensive mobilization efforts requires more resources.
C) The stakes represented by elections are so high because decisions from the federal government affect every aspect of American social and economic life.
D) New campaign finance laws that provide full public financing for all federal candidates has increased the competitiveness of elections since each side is equally matched.