From Donald Trump’s feud with Alicia Machado, to his Access Hollywood grope tape, to the flood of sexual assault allegations against him, the past month has provided so many examples of the Republican candidate’s misogyny as to virtually bury all of the other bad things he’s done over the course of the campaign. With all the news surrounding Trump’s personal grotesqueries, it has been easy then to forget the ugliness of his actual political agenda.

Hillary Clinton wants to remind voters about this before Nov. 8 and a new ad does it in a way that is also devastatingly personal. It is the most vivid, effective, and brutal ad of the campaign season that I have seen.

The 60-second spot takes on one of Trump’s most cynical, malicious, and blatantly unconstitutional policy positions: His proposed ban of Muslims from immigrating to the country.*

It tells the story of Humayun Khan from the perspective of his father, Khizr. If you watched the Democratic National Convention or followed the news coverage in the weeks after, you know the basic outline: Capt. Humayun Khan was killed in Iraq while serving in the U.S. army in 2004. His actions appear to have saved the lives of his fellow soldiers and he was posthumously awarded the Bronze Star and the Purple Heart. Khizr Khan gave the best speech of the DNC, challenging Trump’s Muslim ban, sharing the story of his son’s death, and waving his now famous pocket Constitution before the conventional hall promising to lend it to Trump. The Republican nominee for president of the United States then spent the ensuing week feuding with this Gold Star family.

What this ad does is remind people who were paying attention at the time of one of the most poignant and damning moments of the entire campaign, which may have been lost in the deluge of other news these past months, while introducing the story to voters who are only starting to pay attention now in an extremely powerful way.

While the sad, suspense-laden orchestral score is obviously fairly unsubtle, it feels like an earned backdrop for Khizr Khan’s telling of the story of his son’s death. As he did at the convention, the father is clearly speaking his own words with nothing written from the Clinton campaign, and those words are both spellbinding and crushing. The story is told in simple, straightforward, suspenseful language from beginning to end over images of Khan tending to the affairs of his son, including his uniform and what appears to be the flag that was placed on his coffin at his military funeral, and flipping through photos of Humayun in that uniform. At the end, we see a brief slow-motion image of Trump giving a speech followed by a shot of Khizr holding his arm around his wife, Ghazala, as he watches his son’s military funeral and she puts her head down. Here is the script in its entirety:

In 2004, my son was stationed in Iraq. He saw a suicide bomber approaching his camp. My son moved forward to stop the bomber. When the bomb exploded he saved everyone in his unit. Only one American soldier died. My son was Captain Humayun Khan. He was 27 years old and he was a Muslim American. I want to ask Mr. Trump: Would my son have a place in your America?

That final line is possibly the most damning indictment of Trump of this campaign and during its delivery the ad shows a close-up of Khizr’s face. You see him saying the line with grace and sincerity, but also nearly breaking down at the end. Again, the entire thing is brutal, and it’s hard not to watch without beginning to get teary eyed yourself.

The ad should also be effective in two ways. First, it will remind moderate Republicans of the shame they should feel at the prospect of supporting such a candidate as Trump. In doing that, it should depress them and depress his turnout. There was some of this already when Khan first told his story—the initial reaction to that DNC speech among many moderate Republicans was sadness at how far their party had fallen and it only got worse as Republican after Republican had to distance themselves from Trump’s feud with the family. But that now feels like a long time ago and a lot has happened since then, and this reminds moderate Republicans of what for them was possibly the low point of the campaign.

The second thing this ad does: It should sway undecided Democrats and bolster their turnout by reminding possibly on-the-fence Bernie Sanders voters what the stakes are of this election. These Sanders voters—who were mostly white liberals according to exit polls—will be reminded of the harm a Trump presidency promises to do to purported progressive values of diversity and equality.

It does all of these things in a way that tells a story that is impossible to truly forget but that voters still might have needed to be reminded about before Election Day.

*Correction, Oct. 24, 2016: This post originally misstated that Trump’s ban was on Muslim Americans immigrating to the country.

Read more Slate coverage of the 2016 campaign.