The ads will run in Indiana and Missouri, where Sens. Joe Donnelly and Claire McCaskill are seeking reelection in states where Trump won by nearly twenty points in the 2016 election. The group ran the first wave of ads against the two Senators in February.

The new ads, which will be released on Thursday and run for three weeks, feature testimonials from individuals in the respective states — an Indiana small business owner named Cathy and a working mother of three from Missouri named Lindsay — who argue that tax reform has benefitted them and don’t understand why their Senators voted against it. The ad in Missouri seizes on McCaskill’s comments after she voted against tax reform last year, in which she said she opposed the measure because it gave the working people in her state “scraps” while benefiting the wealthy and corporations.

“When I heard Claire McCaskill describe the tax cuts as ‘scraps,’ I think it’s disrespectful. Getting bonuses and tax cuts — that’s huge for families like mine,” Lindsay, the mother from Missouri, says in the ad.

“As more Americans see the benefits of tax reform, they are rightly concerned to learn that some lawmakers, like Joe Donnelly and Claire McCaskill, voted against tax relief for individuals and families,” said Tim Phillips, the President of Americans for Prosperity. “AFP is committed to holding opponents of tax reform accountable for seeking to deny individuals like Lindsey and Cathy the opportunity to improve their lives.”

The ad buys are part of the network’s $20 million effort to promote the tax bill. This push will be crucial in a midterm election year where history shows the party that holds the White House typically suffers Congressional losses — a dynamic officials with the network have acknowledged.

But the ad push also comes at a time when touting tax reform, which some Republicans deemed one of their only bright spots in a difficult cycle, may not necessarily help as much as initially envisioned, as evidenced by the most recent election.

A Politico analysis of television ads from Tuesday’s special election in Pennsylvania’s 18th Congressional district — which Trump won by double digits in 2016 — found that the percentage of television ads touting tax reform, which were largely financed by outside groups who spent millions in the race, declined as election day inched closer. Despite the conservative leanings of the district and Trump’s 2016 victory, polling showed a tight race — the precise situation where touting the benefits of tax reform would presumably help the Republican candidate, Rick Saccone.

And in the beginning of February, the Politico analysis found, two thirds of the ads centered on tax reform; but by the first week in March, as polls continued to tighten, the groups were only airing two ads highlighting the law.

As of 11 p.m. Tuesday night, the race was still too close to call. Saccone was trailing the Democratic candidate, Conor Lamb, by approximately 800 votes.

(Disclosure: Time Inc., TIME’s parent company, has been acquired by Meredith Corp. in a deal partially financed by Koch Equity Development, a subsidiary of Koch Industries Inc.)