When Hillary Clinton (reportedly) compared Vladimir Putin's actions in Ukraine to those of Nazi Germany, she was doing more than breaking a cardinal rule of public discourse. She was reminding America that she is tough and that Democrats are tough, a debate that was once a prominent thread in national politics and appears, by all available evidence, to be resurgent.
"Hillary doesn't stop at likening Putin's actions in Crimea to Hitler's in 1930s," the AP tweeted about a story documenting Clinton's expansion on her Godwin-upholding comments. "Vladimir Putin is a tough but thin-skinned leader who is squandering his country's potential," the news service summarizes Clinton saying, with her then clarifying that she wasn't actually calling Putin Hitler.
When Clinton ran in 2008, her "toughness" eventually came to be seen as an area of strength. That May, a poll indicated that about as many people saw Clinton as tough as saw Arizona Sen. John McCain that way. Clinton fostered the perception in part to contrast her foreign policy experience with then-Sen. Barack Obama, including in the famous "3 a.m. Call" ad.
But the push to reinforce her strength also lay in two other concerns: her gender and her party. As the Cold War evolved and collapsed, the Democratic Party was consistently portrayed as weak and coddling. There's an enormous amount of psychological complexity crammed into that, and a lot of history. But the short version was: Democrats would rather give up power than fight. Democrats like Jimmy Carter got Americans kidnapped in Iran by being weak. Republicans like Ronald Reagan freed those hostages and tamed urgent threats in Grenada and Libya (for a bit). That idea took hold. It's why Michael Dukakis, running for president in 1988, decided he needed to show his toughness by riding around in a tank. (Which backfired.) It's why in 2004 George W. Bush — who'd more than proven his toughness bona fides by then — went after John Kerry, like McCain a war hero, for being weak and soft and rich. And why the Swift Boat Veterans For Truth worked so hard to raise doubts about Kerry's record in Vietnam.