"I've been looking at some video clips on YouTube of President Obama - then candidate Obama - going through Iowa making promises. The gap between his promises and his performance is the largest I've seen, well, since the Kardashian wedding and the promise of 'til death do we part"

Mitt Romney is making a contrast between President Obama's pledges and his performance, and the guarantees made in a Kardashian wedding. He is implying that President Obama's guarantees have actually not been kept, which the space in between his guarantees and his efficiency is the biggest he has seen given that the Kardashian wedding event. This contrast is implied to be funny, however also to highlight the point that President Obama has not kept his pledges. Romney is suggesting that President Obama's guarantees are not to be trusted, which his performance has not measured up to his pledges. This quote is a criticism of President Obama's record, and a reminder that promises need to be taken seriously.