New Poll Shows Lots of People Having Second Thoughts After Monday's Debate

[See update below.]

The overnight polls all say Hillary Clinton won Monday's debate by a wide margin. Common sense confirms this. But how will this affect the race? Ipsos/Reuters released its first post-debate polling today, and the results are on the right.

Clinton gained ground, which is no surprise. But the truly remarkable thing is that the Undecided vote skyrocketed to 20 percent. After the debate, Trump, Gary Johnson, and Jill Stein all lost huge amounts of support, and only a fraction of it went to Clinton. Most of them are simply no longer sure who to vote for. Apparently a lot Trump supporters saw his performance and had second thoughts, and lots of Johnson/Stein supporters saw Clinton's performance and had second thoughts.

Oddly enough, none of this strangeness showed up in the polling on a two-way race. Nor does Clinton gain any ground in today's PPP poll. So I'm not sure what's really going on.

UPDATE: I'm an idiot. The poll on the right asks people who they think will win, not who they plan to vote for. Sorry about that.

In the actual preference poll, Ipsos/Reuters only did a two-way question, and Clinton lost ground. This is odd considering that in the very same poll voters gave Clinton a big win in the debate and said they were now more favorably disposed toward her. Life is strange.