"The great election-eve middle-class tax cut began not as a factual proposal, but as a false promise," say Philip Rucker and Ashley Parker in The Washington Post. "Yet Washington's bureaucratic machinery whirred into action nonetheless — working to produce a policy that could be seen as supporting Trump's whim."

But "the mystery tax cut is only the latest instance of the federal government scrambling to reverse-engineer policies to meet Trump's sudden public promises — or to search for evidence buttressing his conspiracy theories and falsehoods," the Post adds. "Just this week, Vice President Pence, the Department of Homeland Security, and the White House all rushed to try to back up Trump's unsupported claim that 'unknown Middle Easterners' were part of a migrant caravan in Central America — only to have the president admit late Tuesday that there was no proof at all."

What the American president says doesn't just steer policy, it makes news. And Trump's flurry of untruths before the midterms has created a dilemma for news organizations. Here are some headlines in major newspapers, tackling Trump's overall campaign mendacity or specific lies:

Los Angeles Times: "Trump tries to spur Republicans to vote with false claims and dystopian warnings of Democratic 'mob' rule"

The Washington Post: "'In the service of whim': Officials scramble to make Trump's false assertions real"

The Associated Press: "'Boogeyman' Trump stokes fears in election closing arguments"

The Daily Beast: "Trump's own team knows his caravan claims are bulls--t"

The New York Times: "Trump and GOP candidates escalate race and fear as election ploys"

Politico: "Trump's mystery tax cut puzzles Washington"

The Wall Street Journal: "GOP latches onto vague Trump tax statement as campaign nears end"

Repetition can distort reality, Daniel Effron, an expert on the psychology of lies at London Business School, tells the Post. "When falsehoods feel familiar, one concern is you don't actually know what's true and what's false." But the truth is out there. Peter Weber