Democrats sat out the tax fight. It may prove to be an epic policy and political blunder

Democrats have a lot to say about the Republican tax-reform plan, including that it is a “middle class con job” and is going to cost the GOP its congressional majorities. That’s quite the bold claim, coming from the party that is in fact in uncharted tax-politics territory.

Americans have short political memories, which means it is no longer possible to remember a world in which Democrats didn’t hate tax cuts. And in the mainstream media—which shares the left’s penchant for class warfare—it’s also no longer possible to read an analysis that doesn’t assume Democrats are on the right side of history, that these tax cuts are “unpopular,” and that this reform holds grave political risks for Republicans.

In short, there is very little to suggest Democrats benefit politically from sitting out this tax debate—beyond their saying so. And they’ve certainly done themselves no favors from a policy perspective.

Based on what? Democrats certainly have no modern evidence of these propositions, since they’ve never uniformly opposed tax cuts. In fact, it’s been 16 years since the party even engaged in a big tax brawl, during George W. Bush’s first year as president. What’s striking is just how many Democrats enthusiastically signed on to Mr. Bush’s tax bill, and just how far off the political rails the party has gone in the intervening years.

While the Bush tax package was hardly as sweeping as today’s reform, it contained similar provisions. It cut marginal rates across the board, even knocking nearly 5 points off the top marginal rate for the 1 percent. It cut capital-gains taxes and lowered the estate tax to zero in 2010, before the reductions expired. These are all cuts that House and Senate Democrats today uniformly decry as giveaways to the rich and powerful.

Keep reading Kimberley Strassel's column in the Wall Street Journal.