With health care, the stakes were much clearer.
The tax bill has "been much more of a challenge," said TJ Helmstetter, spokesperson for advocacy group Americans for Tax Fairness. "Because health care took so much of the year, and rightfully took up so much oxygen, it's been harder to get people focused."
During the health care debate, activist groups could point to clear numbers of people who would lose health insurance if Obamacare was repealed. In that respect, Senate Republicans adding the individual mandate to their tax bill has certainly helped focus people's attention.
"For this, it's every bit as dire, but just a little more complicated to explain," Helmstetter said.
Progressive groups are also being outspent by pro-tax cut groups with deep pockets, including the US Chamber of Commerce and the billionaire Koch brothers, Helmstetter added. The lack of attention also has to do with the incredibly fast pace that Republicans are moving on taxes in both the House and Senate. Democratic Sen. Tim Kaine of Virginia underscored that last week, as the Senate Finance Committee recently approved the tax bill in a late-night session.
The big thing that progressive groups have on their side now is the unpopularity of the House and Senate tax plans, and the fact that they give advantages to corporations over the middle class. A recent poll from Quinnipiac found that most Americans don't like the House and Senate proposals. Outside analyses have estimated that more than 25 percent of taxpayers would pay more by 2027 under the House bill, while the Senate bill is projected to raise taxes on poorer Americans who make less than $30,000 a year starting in 2021.
And Democrats are sounding the alarm about the tax plan triggering massive cuts to entitlement programs, after the nonpartisan Congressional Budget Office said the tax plans could trigger a $25 billion cut to Medicare.
"This is like a one-two punch, and the best way to stop the second punch is to stop the first one," said Ben Wikler, Washington director of MoveOn.org, one of the left's biggest advocacy groups.
As dramatic as those projections are, it's given Democratic activists groups a clear message to rally around: Republicans want to cut taxes for the rich, and they're going to do that by raising taxes on the poor (and gut health care coverage along the way).
There's plenty of independent analysis to support this. A recent Tax Policy Center estimatefound that the individual tax cuts in the House plan would overwhelmingly benefit the top 1 percent 10 years from now. At the same time, millions of US households of middle- and working-class families would eventually see their taxes raised, according to analysis from the New York Times.
"It's like they are trying to make this bill as bad as possible, and that reminds me of the track we were on with health care," said Tim Hogan, spokesperson for Not One Penny, a coalition of progressive groups fighting against the tax bills.
Activist groups say they're somewhat surprised with how brazen some Republicans have been about revealing the reasons they are supporting the bill. For instance, earlier this month, Rep. Chris Collins (R-NY) told reporters, "My donors are basically saying, 'Get it done or don't ever call me again.'"
Congressional Democrats and activist groups have jumped on Collins's line, saying it shows that Republicans aren't even trying to hide the intent of their bill.
"Republicans are talking to rich Republican donors more than they're talking to their constituents," Wikler said. "You'd think they'd look out the window and notice the people chanting outside."
Earlier this year, there was some fear among progressive groups that Senate Democrats from pro-Trump states would feel the pressure to support a Republican tax bill, as Jeff Stein wrote for Vox. But that fear has since been alleviated; progressive groups say they're feeling confident that more conservative Democratic senators won't support the current tax bill, leaving them free to focus on convincing Republicans.
But they're also looking toward Democratic senators to get a lot more antagonistic and even potentially hold up Senate process, depending on how far the bill gets.
Progressive groups ran into a problem with a slow-down in media attention to their cause during the health care bill as well, in large part due to a chaotic news cycle dominated by President Donald Trump.
Much like that time, the news cycle is dominated by chaotic stories, like the sexual assault allegations against Republican Alabama Senate candidate Roy Moore, and now the Democrats' own Sen. Al Franken of Minnesota. That makes it tough to get the same level of coverage on the tax bill — much less tax activism.
"There's been such a blizzard of news, a lot of Washington hasn't realized the intensity of activism against the tax bill yet," Wikler said.
That's where Senate Democrats could come in. As the health care bill was speeding its way through the Senate without hearings or CBO analysis, Democrats made a huge stink about it. In the middle of June, Democrats announced that they essentially were holding Senate process hostage; withholding consent on legislative business and therefore shutting down the normal operations of the Senate. They also started invoking something known as the two-hour rule, which cut short the time Senate Republican committees had for their hearings.
"All of that helped focus the attention where it needed to be," Padilla said. Now, with taxes, he's hoping Democrats will get off the sidelines. "We don't want them to watch this play out."