President Trump's Twitter tirades might sound like the ranting of a mentally unstable person, but they might actually be the cunning tactics of an especially slick politician. That's because spouting alt-right extremism actually makes the average person more receptive to less radical but nevertheless abnormal political views, according to a concept in political science called 'The Overton Window.'

Basically, the theory says that you can make people accept radical positions by pitching them alongside more extreme stances. That way, the less-extreme positions seem normal, even though they are a stark contrast from the status quo. For example, you'd be pretty upset if you were served a bologna sandwich for Christmas dinner this year. But if your family said the only other option was a rotten carton of eggnog, then that sandwich would start looking pretty good. And so do Trump's radical policies when compared to his more extreme views.

In the last year, Trump has defended white supremaciststhreatened nuclear war on Twitter and retweeted anti-Muslim propaganda. Each one of those issues is enough to make your blood pressure spike. And they can also make you less anxious about Trump's tax plan, which is already being called a cash-grab for the Republican Party's wealthiest donors. But since the bill doesn't spout threats against North Korea or stereotype all Muslims as terrorists, it seems reasonable by comparison.

And that normalization is bad news for Democrats. As the political spectrum shifts further right, hardline conservatives that would've been considered ideologues a decade ago now look like voices of reason within the Republican Party. 

For more on Trump's use of the 'Overton Window,' check out the video above.

h/t Vox