Measuring the Drapes

New McCain stump speech:

Senator Obama is measuring the drapes and planning with Speaker Pelosi and Senator Reid to raise taxes, increase spending — take away your right to vote by secret ballot and labor elections, and concede defeat in Iraq

I was non-metaphorically laying the groundwork to hang some curtains earlier today and it occurred to me that I don’t quite get this metaphor. I’m measuring my window and hoping to get appropriately sized curtains. What are you going to accomplish by measuring the drapes? You can’t make your window smaller.