Spending money like Teabag water: If Rubio can't balance his checkbook...

Mitt Romney and Mr. Rubio arriving in Kissimmee, Fla., on a presidential campaign stop in October 2012. Mr. Romney's campaign flagged Mr. Rubio's financial issues when vetting him as a possible running mate Debtors' ability to identify with Rubio's financial imprudence doesn't speak well for his ability to manage a national economy WEST MIAMI, Fla. — For years, Senator Marco Rubio struggled under the weight of student debt, mortgages and an extra loan against the value of his home totaling hundreds of thousands of dollars. But in 2012, financial salvation seemed to have arrived: A publisher paid him $800,000 to write a book about growing up as the son of Cuban immigrants.

In speeches, Mr. Rubio, a Florida Republican, spoke of his prudent plan for using the cash to finally pay off his law school loans, expressing relief that he no longer owed “a lady named Sallie Mae,” as he once called the lender.

But at the same time, he splurged on an extravagant purchase: $80,000 for a luxury speedboat, state records show. At the time, Mr. Rubio confided to a friend that it was a potentially inadvisable outlay that he could not resist. The 24-foot boat, he said, fulfilled a dream...

These were not isolated incidents. A review of the Rubio family’s finances — including many new documents — reveals a series of decisions over the past 15 years that experts called imprudent: significant debts; a penchant to spend heavily on luxury items like the boat and the lease of a $50,000 2015 Audi Q7; a strikingly low savings rate, even when Mr. Rubio was earning large sums; and inattentive accounting that led to years of unpaid local government fees.