Biden isn't pulling negative ads to be nice. Biden is pulling negative ads because the last thing he wants to do is make his campaign tactics the story, and because negative ads aren't going to be effective in the next few days anyway.

A bunch of folks have replied to this tweet asking why Trump is leaving his negative ads up (or why he's done similar stuff in the past), if Biden taking them down is such smart politics. There's at least four reasons.

First, Trump ran an ugly campaign in 2016 in part because he didn't need a majority to win. He alienated great swaths of voters, took 46% of the vote, and won the White House. If Biden gets 46%, he loses in a landslide. Different rules, different objectives, different tactics.

Second, Trump is losing right now, and was losing most of the way through 2016. When you're losing, you do stuff that probably won't work, because the status quo is even worse.

If I've spent months down by four points, and my people bring me a tactic that will probably lose me five MORE points, but might just possibly net me five points, I run with it. Because losing by nine is no worse than losing by four. It's a good bet, even if the odds suck.

Third, Trump is the one who's sick, so the downside of negative campaigning is mitigated, and the benefit of "going positive" is basically nil. Biden has gotten a bunch of good press for pulling his negative ads. That's useful. Would Trump get that for following suit? Not really.

Fourth: Donald Trump kind of sucks at electoral politics. A lot of the stuff he does hurts him. He wants the adulation of his base more than he wants the support of the uncommitted, and he has no idea what the uncommitted are looking for, anyway.

There's lots of stuff I'd like to see Biden do because it would please me or comfort me or relieve my anxiety about what kind of president he'd be likely to be. But his not doing that stuff doesn't mean he's a bad campaigner. It just means his interests and mine diverge.

Has Biden made mistakes? Sure. Does he have weaknesses as a candidate? Absolutely. Do I wish someone else had won the nomination? Damn straight. But the available evidence suggests his team are doing a lot of stuff right, and the arguments for pulling the negative ads are strong.

Just one more thing on this. I see a lot of people saying "Biden says he's pulling his negative ads out of respect," and similar things, but I've poked around quite a bit and haven't seen any such statement. Maybe the campaign made an announcement I missed, but I don't think so.

They pulled the negative ads, and confirmed that they'd done so when asked by reporters. That's what I've seen. The suggestion that they were doing so because they didn't want to be mean to Trump seems to me to be an inference—a false inference, I'd argue—presented as fact.