I remember back in 2008 when they were voting for TARP. The first vote failed and the stock market crashed. So they put a bunch of pork into it and voted again saying DON'T FUCK THIS UP GUYS LAST TIME YOU FUCKED IT UP AND YOU CAUSED THE STOCK MARKET TO CRASH. So they voted for it this time and the stock market crashed again. I was watching it on C-SPAN while monitoring the market.
They want to play on people's fear and point to the markets around the world reacting negatively to try to change the vote. But I think the market reaction was more about the uncertainty than anything else. Long term the financial impact won't be a very big deal. They will make trade agreements with the EU to effectively get back to the same place.