Lowering import duties would lower costs for consumers. And in the long term, help US companies to be more competitive. The "trade deficit" isn't actually a problem.

There is no way Mexico is going to 'buy more from the US' than the US 'buys from Mexico' the US is way wealthier so has more to buy...

The problem of the 'trade deficit' is actually a budget deficit... but that is not an economics problem. It is a political problem.

Most federal spending is in Medicare, Social Security, and Defense... but if you're a politician good luck cutting spending in those areas.

As far as infrastructure and education goes... there is a huge shortage of skilled tradespeople. Electricians, welders, master plumbers... there aren't enough in the US so that's what people do to get better jobs... and the government should help them. "The debt" doesn't matter at this point. Either the US gets more competitive... or it won't matter in the long run anyway.

The big threat the US faces isn't necessarily excessive borrowing (although that is an issue) it's lack of global competitiveness.

And the solution if there is one is investments in education, infrastructure, and new technologies.

If that doesn't get sorted out, the debt will never get repaid and the US is cooked regardless.

If it does get sorted out... (and the US becomes more competitive again) the debt is still significant but it will be OK eventually. People will still buy US debt even if it looks like a "bad idea".

A more competitive US and people will be eager to buy it for what it's worth.