Abortion rights demonstrator Elizabeth White leads a chant in response to the Dobbs v. Jackson Women's Health Organization ruling in front of the Supreme Court on June 24, 2022.
CNN  — 

If you want to understand what political parties and their candidates believe will decide elections, pay attention to the issues they are talking about on TV.

TV ad buys are (still) the biggest expenditure most campaigns make. So, they don’t waste money on messages they don’t think will work.

Which is what makes the amount of money that Democratic groups and candidates have spent on ads highlighting the Supreme Court’s decision to overturn Roe v. Wade so incredibly telling and important about their midterm plans.

Since the court’s ruling on June 24, Democrats have spent almost $66 million on more than 250 ads that mention abortion, according to figures from AdImpact compiled by CNN’s David Wright. That’s six times – yes, SIX – the amount of money Republicans have spent on commercials centered on the issue over that same period of time.

A few samples of the sorts of the ads Democrats are running:

* In Alaska’s lone House seat, Democratic Rep.-elect Mary Peltola is up with an ad in which she says “nearly 4,000 miles away, six Supreme Court justices took away one of Alaska’s most fundamental freedoms: Our right to choose. That’s a game changer.”

* In the Nevada Senate race, the Democratic Senatorial Campaign Committee released an ad bashing GOP nominee Adam Laxalt for his “praise of the Supreme Court’s decision overturning Roe v. Wade,” and noted that called the original decision a “joke.”

* Another ad from the DSCC in the Arizona Senate race features a testimonial from a woman who chose to have an abortion. “Blake Masters has no idea what I went through, and he has no business making that decision for me or any woman,” she says, referring to the Republican nominee.

The early political returns for Democrats have been promising. A bid to remove abortion protections from the state constitution in Kansas via referendum failed miserably over the summer. A special election in upstate New York – in which the Democratic candidate ran expressly on the Roe decision – turned into a surprising victory for President Joe Biden’s party. And even in Alaska, which has long been a conservative stronghold, Peltola won a special election over a field that included former GOP Gov. Sarah Palin for the remaining few months of the term of late Rep. Don Young.

It’s not just anecdotal evidence that suggests Democrats’ big bet on abortion is paying off. After trailing on the generic ballot (“If the election was today, would you support the Democrat or Republican candidate for Congress?”) for much of the last year, Democrats are suddenly leading – albeit narrowly – on the question in some polls. For instance, a recent Wall Street Journal survey showed 47% of registered voters favoring Democrats and 44% favoring Republicans.

Much of that movement is among women, and in particular independent women. As Wall Street Journal polling director Aaron Zitner explained:

“Abortion has emerged as an important issue in motivating the votes of many people, including women in political swing groups. Women who are independents, for example, shifted 20 percentage points in the Democrats’ direction, and Hispanic women moved by 15 points.”

There’s no debate that the Supreme Court’s abortion ruling has brought Democrats back from the brink of what looked like – as recently as the start of the summer – a political cataclysm. Most nonpartisan political handicappers see the fight for Senate control as a genuine toss-up. House Republicans are still given the edge in the race for the lower chamber, but predictions of massive seat gains have withered.

The question now is whether abortion as a motivator for the Democratic base – and independent women – will sustain for the next 62 days. Democrats are betting – and betting big – that it will.