Elections change the political conversation in slow motion—as candidates decide to run, as they appeal for votes, as they translate words into action after taking office.
But horrifying events in the world—like this week's attacks in Paris—change it instantly.
Congressional Republicans had established February as the month that funding for the Department of Homeland Security would run out as they seek to block President Barack Obama's executive action on immigration. Their chances of succeeding were always dim; now they are dimmer.
"I've never been for shutting down Homeland Security," Republican Sen. Lindsey Graham of South Carolina said in one television interview. As a top Senate Democratic aide put it, "It makes it harder to talk about defunding with a straight face."
The brazen killings at the French magazine Charlie Hebdo put pressure on Obama in different ways. Just as improving economic numbers were beginning to brighten the public mood, fear of terrorism could dampen it again,