"Can the US pay it's debt?" is the wrong question. The US can pay off any amount of debt, because their debt is measured in USD and congress can issue new USD as needed.
"How does the debt actually effect the economy? (Does it?)" and "What is the long-term impact of various debt-maintenance strategies?" and "Will political deadlocks prevent effective management of the debt?" (among many others) are better questions.
"How does the debt actually effect the economy? (Does it?)" and "What is the long-term impact of various debt-maintenance strategies?" and "Will political deadlocks prevent effective management of the debt?" (among many others) are better questions.