"Since Obamacare was enacted emergency room use has gone up, not down as predicted."
And it's not like there wasn't evidence to show this would happen. Studies of the Massachusetts plan showed ER visits went up after implementation. When compared to neighboring states without "Romneycare" there was no difference in ER visit rates except that ER visits that resulted in admission went up at a much higher rate in Mass.
To dispute Tony's point about Medicaid expansion, a study of expanded Medicaid in Oregon show not only increased ER visits, but increased primary care visits; more healthcare usage across the board.
Granted, the length of those studies is relatively short; over time those stats could change I suppose...