Hillary Clinton would like voters to believe she's the candidate most likely to help working Americans. After a surprisingly difficult primary fight with a socialist senator from Vermont, Clinton has adopted a lot of populist economic rhetoric. On her campaign website, she says she has an eight-point plan to help the middle class, with the first point saying, "Hillary is proposing middle-class tax breaks to help families cope with the rising cost of everyday expenses." However, Clinton actually hasn't ever released her plan to cut middle-income taxes (or really any taxes), instead relying on evasive answers and proposals for small-change tax expenditures.
Nowhere in Hillary's plan for a raise for the middle class does her campaign discuss lowering any income tax rates. In fact, she most often talks about raising taxes on the wealthy. She talks about expanding child care credits and making college affordable. She touts her support for unions, clean energy, and infrastructure, but doesn't really make it clear how those would increase voters' take-home pay.
In March the Clinton campaign released a tax plan that would raise $1.1 trillion in new taxes. She told the Tax Policy Center that an income tax cut for low- and middle-income families was forthcoming. We're still waiting.
On September 22 Clinton updated her tax plan again, this time spelling out major changes to the estate tax (mirroring a plan put forward by Bernie Sanders). But she still didn't talk about her promised middle-income tax cut. And her campaign has hinted in some places that what you see is what you get. The tax credits for "everyday expenses" that she has outlined in disjointed fashion throughout the Democratic campaign and general election might be her only version of a tax cut for the middle class.
Hillary's reluctance to commit to a specific tax cut for the middle class could be related to her husband's 1992 campaign. During the battle with President George H. W. Bush and Ross Perot, Bill Clinton pledged to cut taxes for most Americans, while fighting the deficit. Once he was in office, however, his plan changed almost entirely to deficit reduction. In fact, President Clinton's 1993 budget was a massive tax increase (albeit one that contributed to the first surpluses in decades by the time he left office). The backlash to that budget, along with a failed carbon tax and healthcare reform plan, propelled Republicans to seizing both chambers of Congress for the first time in 40 years. Maybe Hillary Clinton would like to avoid repeating that mistake. Perhaps she, probably accurately, sees that deficit reduction and new spending needs will trump any desire for broad tax relief and doesn't want to get caught up defending a flip-flop in 2018 and 2020.
Another possibility, which isn't mutually exclusive from learning from her husband's experiences, is that Hillary Clinton simply isn't all that committed to tax relief. Rifle-shot tax expenditures that sound good, but don't cost the government that much revenue, have always been among the Clintons' favorite political gambits. Perhaps that's all Hillary thinks she needs to talk about to win over populists who were backing Sanders or who might be thinking of supporting Donald Trump.
If that's the case, then Clinton owes it to voters to make it clear that no new plan is coming. And voters who believe that actual tax relief is a key part of fighting inequality or increasing take-home income need to look elsewhere.