The national debt surpassed a record $40 trillion on Wednesday, a staggering milestone as defense costs, social programs like Social Security and Medicare and interest on the burgeoning deficit to make up an enormous share of federal spending.

The federal debt reached $40 trillion as the government adds red ink at a rapid rate. That's leading nervous investors to demand higher interest rates —pushing up borrowing costs…

Federal debt has mounted amid tax cuts and trillions in pandemic spending, adding to the nation's interest payments.