Democrat Casey says the greed of “big conglomerates” is to blame for high prices for household essentials. Republican McCormick claims the economy is “weak.”

Democrat Bob Casey and Republican David McCormick are facing off in a race that could decide which party controls the U.S. Senate.

The race between three-term Democratic incumbent Pennsylvania Sen. Bob Casey and Republican challenger Dave McCormick is now rated a toss up — and the self-described “underdog” tells The Post he expects only more gains at the polls.