Two things are clear about Social Security and Medicare: The pillars of America's safety net for seniors still face cash flow problems. And because Congress won't correct them in this election year, the presidential candidates' views about this challenge are crucial.

The trustees for Social Security and Medicare reported last week that the programs remain on course to run out of payroll tax revenues to pay full benefits: Social Security in 2041 and Medicare's hospital fund in 2019.

Both get into trouble even earlier than that. Social Security starts paying out more in benefits than it receives in payroll taxes in 2017. Medicare reaches that tipping point this year.

John McCain has done the most to discuss the problem and offer answers — not to mention walking the walk with tough votes.

The Republican has given at least two significant addresses on the challenge. One especially took guts — appearing before the AARP with charts and graphs. McCain starts with an overhaul of the health care system but drills down to specifics such as reforming how Medicare pays for services. His list includes stopping payments to hospitals when their mistakes inflate a medical bill.

His votes include one requiring seniors to pay more of their Medicare premiums and one favoring raising the age at which Americans can receive Medicare.

Hillary Clinton and Barack Obama voted against the former bill and were not in the Senate at the time of the age vote. They believe that better information technologies will help control Medicare's finances and that improving health care will ease its burden.

We don't quarrel with those thoughts, but neither Democrat is talking about hard choices, such as asking seniors to pay more for services. In fact, Obama wants Washington to spend more to help seniors afford prescription drug benefits. How he can do that without increasing Medicare's financial problems is a mystery.

Each candidate needs to speak more about the entitlement challenge, including explaining to younger Americans how they will wind up bailing out Social Security and Medicare if nothing is done soon. Even McCain can say more, given the problem's scale.