Cummings and his fellow liberal liars are referring specifically to the final fiscal year 2012 omnibus appropriations package
I've taken great pains to be non-partisan on this, but if you want to start by implying that everyone who disagrees with you on substance is a "liberal liar," fine. I'll play along.
First, you need to understand what an Omnibus Appropriations Bill is, and how the party controlling congress has near total control of its content.
Every year, Congress must pass bills that appropriate money for all discretionary government spending. Generally, one bill is passed for each sub-committee of Appropriations, one bill for Defense, one for Homeland Security, etc.
However, when Congress can't produce separate bills before the beginning of the fiscal year on October 1, it will roll all the separate appropriations bills into one omnibus spending bill. These bills can easily reach 2,000 pages.
So, of course many democrats voted for it. It was over 2,000 pages long and contained spending on every possible government activity, not just embassy security. However, since Republicans controlled congress and all the sub-committee chairs, they must claim ultimate responsibility for what's in the bill. That's just how congress works. You want control of the House? You take the credit and the blame. Big boy rules.
Romney knew this. It's why he didn't raise the issue in the debate. Again, I wish he had.