Washington The Democratic candidates for president gathered in Des Moines, Iowa, for their second debate Saturday, and CNN's Reality Check team spent the night putting their statements and assertions to the test.

The team of reporters, researchers and editors across CNN selected key statements and rated them: True; Mostly True; True, but Misleading; False; or It's Complicated.

Previous CNN Reality Check coverage of the Democratic and Republican candidates can be found here . This story will be updated throughout the night.

Hillary Clinton

Reality Check: Clinton on minimum wage

By Tami Luhby, CNN Money

Former Secretary of State Hillary Clinton threw her support behind a $12 hourly minimum wage at Saturday's debate. That's lower than the $15 an hour minimum backed by Vermont Senator Bernie Sanders and former Maryland Governor Martin O'Malley, as well many progressive activists nationwide.

Clinton defended her stance, saying: "If you go to $12, it would be the highest historical average we've ever had." That's the "smartest" way to move forward, she added.

So has the minimum wage ever reached $12, even after adjusting for inflation? The answer is no. The highest it ever got was way back in 1968 when it was $1.60. That may seem low, but in today's dollars it was $10.86.

Verdict: True

Bernie Sanders

Reality Check: Sanders on vets with PTSD

By Debra Goldschmidt, CNN Health

Vermont Sen. Bernie Sanders said, "When you talk about the long-term consequences of war, let's talk about the men and women who came home from war, the 500,000 who came home with PTSD and traumatic brain injury."

Roughly 2.6 million veterans served in Iraq and Afghanistan , and the U.S. Department of Veteran Affairs says 11% to 20% of military members who served in Iraq and Afghanistan suffer from PTSD.

According to a Veteran Affairs independent study on traumatic brain injury, self-reported data found 15% of troops who were engaged in active combat in Afghanistan and Iraq "may have suffered" a mild traumatic brain injury. This falls in line with a report from the Brain Trauma Foundation, which found between 10% to 20% of Iraq veterans suffer from some level of traumatic brain disorder.

Verdict: True

Reality Check: Sanders on Muslim countries fighting ISIS

By Eve Bower, CNN

Vermont Sen. Bernie Sanders said, "The Muslim nations in the region -- Saudi Arabia, Iran, Turkey, Jordan -- all of these nations, they're going to have to get their hands dirty, their boots on the ground. They are going to have to take on ISIS. ... Those Muslim countries are going to have to lead the effort. They are not doing it now."

Launched in September 2014, the U.S.-led coalition fighting ISIS consists of more than 60 coalition partners, including more than a dozen Muslim-majority countries. All of the countries Sanders mentioned are part of that coalition -- with the exception of Iran, which has been countering ISIS in separate initiatives that include training, advising, and supporting Iraqi and Syrian forces fighting ISIS.

The actual contributions of each member of the U.S.-led coalition vary widely. As of October 2014, Saudi Arabia's contribution consisted of warplanes and training for Syrian rebels fighting ISIS. They also donated $500 million to UN humanitarian efforts in Iraq. Turkey has allowed foreign troops to launch attacks against ISIS from within its borders, and in July, began launching its own airstrikes against ISIS in Syria. Jordan launched airstrikes against ISIS early in the campaign, but later suspended its participation when one of its aircraft went down in Syria and one of its pilots was taken hostage. Jordanian strikes resumed after ISIS announced it had killed the Jordanian pilot.

Few of the coalition's members have contributed active ground troops. In 2014, Egypt sent forces to Libya to bomb ISIS positions there. In late October, the United States authorized the deployment of about 50 special operations forces to northern Syria to fight ISIS. The Obama administration is also considering a special forces task force to fight ISIS in Iraq.

In June of 2014, Iraqi officials said that Iran had sent about 500 Revolutionary Guard troops to fight alongside Iraqi troops against ISIS. The Iranian Foreign Ministry denied this, but Iran's president said Iran was prepared to help advise Iraq if asked.

Sanders is correct that, at present, the primary coalition fighting ISIS is led by the United States. But several of the Muslim countries in the coalition have lost soldiers and civilians in the battle against ISIS.

Verdict: True, but misleading

Martin O'Malley

Reality Check: O'Malley on net immigration from Mexico

By Sonam Vashi, CNN

Former Gov. Martin O'Malley said, "The truth of the matter is net immigration from Mexico last year was zero." He then challenged viewers to fact-check him, and we couldn't resist.

According to the Pew Research Center , net migration from Mexico probably reached zero in 2010, and more Mexicans have left the United States than arrived since then.

Additionally, the actual number of Mexicans living in the United States consistently declined throughout 2014. The U.S. Border Patrol also reported that in the 2014 fiscal year, the number of Mexicans apprehended along the border decreased 14% when compared to the 2013 fiscal year.

The information we have suggests that the net immigration rate is negative -- which is actually not zero -- but it is close, and probably still supports O'Malley's point.

Verdict: True

Reality Check: O'Malley on Maryland's median income

By Tom LoBianco and Tami Luhby, CNN

Former Maryland Gov. Martin O'Malley often goes back to his record as governor to explain how he would best shepherd the nation's economy in the White House. But he went a step further than he typically does during Saturday night's debate and took credit for Maryland's high median incomes.

O'Malley was answering a question of how precisely he would freeze college tuition around the nation and whether his blueprint from Maryland would work across the U.S.

"The blueprint in Maryland that we followed is we raised the sales tax by a penny and made our public schools the best public schools in America for five years in a row with that investment. And yes, we did ask everyone -- the top 14% of earners in our state -- to pay more in their income tax and we were the only state to go four years in a row without a penny's increase to college tuitions," O'Malley said.

The answer, nationwide, is paying for priorities by taxing capital gains income like normal income, he said.

"I believe capital gains, for the most part, should be taxed the same way we tax income from hard work, sweat and toil," O'Malley said. "And if we do those things, we can be a country that actually can afford debt-free college again."

But in the exchange he also took credit for the state's median income level -- long the highest in the nation.

"So while other candidates will talk about the things they would like to do, I actually got these things they would like to do. I actually got these things done in a state that defended not only a AAA bond rating, but the highest median income in America," O'Malley said.

There's no question that Marylanders have done, on average, much better than those in other states since the recession. It's actually had the highest median income every year since 2006, when the median income was $65,144, to last year, when it was $73,971.

In his answer, O'Malley did not explain how his economic plan kept high-wage jobs in Maryland.

But President Barack Obama and former President George W. Bush may be better able to make that claim because of the large share of federal employees in Maryland. A "Governing" magazine analysis of federal employment statistics from 2013 determined that Maryland had the largest share of federal workers for the total workforce of any state, something that the governor has nothing to do with.

Maryland had 145,300 people working for the government, equal to 5.5% of the state's total non-farm employment. Virginia had more federal employees -- 172,500 -- but they only accounted for 4.6% of the total state employment.

And a Washington Post review of federal salaries found that federal workers do quite well compared to many other industries -- earning an average salary of $78,500 as of 2012.

Verdict: False