Indiana Governor Mike Pence, Donald Trump’s vice-presidential running mate who has the task of defending Trump at a debate tonight against Democratic VP pick Senator Tim Kaine, once lost an election over a scandal in which Pence diverted funds from his campaign donors for his own personal use.

Here’s what you need to know about the Mike Pence campaign finance scandal.

1. The Scandal Almost Derailed Pence’s Young Political Career

via @npr: Mike Pence Releases His Tax Returns; Donald Trump Still Won't Trump is hiding a scandal https://t.co/lOP2LqEe8T — TenaciousEye (@TenaciousEye) September 11, 2016

The Washington Post revisited the scandal from 1990, when Pence was making his first run for congress, opposing Democratic incumbent Philip R. Sharp. Much of the then 31-year-old Pence’s strategy consisted of attacking his opponent as beholden to special interests who donated to his campaign.

And then the tables turned. Pence himself was smacked with a campaign finance scandal, with records revealed showing that he had diverted about $13,000 in donations toward his own personal expenses. The revelations sunk Pence’s campaign.

“Without question, he may well have won the election if it had not been for that,” Sharp’s campaign manager Billy Linville told The Post. “It was a bombshell, for sure.”

2. He Used Campaign Funds To Pay His Mortgage — and Other Expenses

So what was the scandal? What was Pence doing with those campaign funds that caused him to be crushed by Sharp in the election 26 years ago?

The campaign finance documents unearthed at the time showed that Pence spent $12,867 of donor cash — which would be more than $23,000 in 2016 money, according to the Consumer Price Index Inflation Calculator — to help pay down the mortgage on his house, as well as on such expenses as fees to take part in golf tournaments and even groceries for his home.

His mortgage payment was $992 per month, and he made seven payments using diverted campaign donations. Pence’s wife, Karen, also had a monthly car payment of $222, and Pence used his campaign funds to make seven of those payments as well. Other campaign donations went to help pay down Pence’s credit cards.

3. Pence Did Nothing Against the Law

Though Pence took funds donated by private citizens who thought their money was going to help get him elected, and spent that money on himself and his wife, Pence’s scandal may have shocked Indiana voters — but the upstart politician did not break any laws in existence 26 years ago. At the time, it was actually legal to spend campaign donations on pretty much anything.

After losing his election that year by a crushing 19 percentage points, Pence called his shady spending “an exercise in naiveté.” But he didn’t exactly apologize for what he did.

“I’m not embarrassed that I need to make a living,” he said at the time, explaining that he had cut back on his legal work in order to run for office, so money was tight.

The Federal Elections Commission has since put rules in place to prevent the diversion of campaign funds for personal use.

4. Pence’s Net Worth Shows That Unlike Trump, He Is Not a Wealthy Man

What Is Mike Pence's Net Worth? – FOXBusiness https://t.co/qysW7Ovhj0 — US Business News (@US_Business) October 2, 2016

Donald Trump’s net worth is the subject of considerable speculation, including by Trump himself. Though he has claimed a personal net worth of $10 billion, Trump himself has admitted that he relays isn’t so sure, and that he estimates his net worth based on his “feelings.”

“My net worth fluctuates, and it goes up and down with markets and with attitudes and with feelings, even my own feelings,” he said in a legal deposition for a 2006 lawsuit.

By contrast, his vice-presidential running mate’s far more ordinary net worth is easier to estimate.

According to a study by The Motley Fool financial site, Pence’s net worth falls somewhere in the $500,000 to $1 million range — but almost none of that is not available cash but rather held in his Indiana state pension account.

He declared a salary of $113,026 as Indiana governor, and he also has a personal bank account containing under $15,000. He has two educational savings accounts for his kids, also each with less that 15 grand. Pence also carries around considerable debt, in the form of student loans for his two kids. His seven student loans range from $10,000 to $50,000 each.

5. Pence Appears to be in the Pocket of Certain Big Donors

“I do not support an expansion of gaming in Indiana" – Mike Pence…before he was boosted by casino industry cash https://t.co/pKDZ9YOtSH — David Sirota (@davidsirota) October 4, 2016

As a hardline conservative, Pence as governor opposed the expansion of gambling interests in his state. But according to a report Tuesday in The International Business Times, Pence took a much softer line once casino industry cash began flowing into his political coffers.

“Since 2011, Pence received roughly $2.2 million from Indiana gaming operators and their lobbying firms,” the IB Times reported. “That includes about $490,000 from nine gaming-linked lobbying firms and their employees directly to Pence’s campaign; at least $360,000 more from gaming industry lobbying firms and their employees to the Indiana Republican Party; and $1.4 million from Indiana gaming interests and their lobbying firms to the RGA, which backed Pence’s gubernatorial bids.

“With that money flooding into the state, the governor helped Indiana’s gaming industry just when it was facing increased competition from neighboring states.”

Pence has also been a committed advocate for the tobacco industry, going so far as to call the link between cigarette smoking and illness “hysteria,” once writing an op-ed piece arguing that “smoking doesn’t kill” and denying that medical research has found any link between smoking and lung cancer.

Tobacco industry groups have contributed more than $100,000 to various Pence campaigns, a report by the Think Progress political site found.