II. (B) if the economy doesn't improve, then (C) the people will blame President Obama.
III. (C) If people blame President Obama, then (D) they will vote for his opponent in the election.
IV. (D) If people vote for President Obama's opponent, then (E) Republicans will take the White House.
Obviously... Republicans want to block any plan that might improve the economy. If you really want to know who to blame for the continued malaise of the economy, look no further than the GOP.