Republican members of Congress congratulated one another and President Trump for passing the House GOP's tax bill on Nov. 16. Before the bill can go to President Trump's desk, the Senate and the House must pass the same bill. (Jenny Starrs/The Washington Post)

A Republican tax plan has passed the House, but obstacles remain in the Senate. One of those obstacles: The plan appears to be not just unpopular, but also distinctively — almost historically — unpopular.

My fellow George Washington University political scientist Chris Warshaw compiled public polls capturing support for major legislation dating back almost 30 years. Here’s what he found:

On average, only about 30 percent of Americans support the tax plan. This is lower than support for almost any of these legislative initiatives. The only thing that was less popular was … the Republican health-care bill that was intended to replace the Affordable Care Act. We know how that turned out.

Depending on the poll, about a quarter of Americans do not have an opinion of the plan. Warshaw accounted for that in a second graph, which captures the net support for the plan (percentage favorable minus percentage unfavorable).

This graph shows the same thing.

If you drill down into individual polls, you can see the specifics of the public’s skepticism: Majorities of Americas believe that the GOP tax plan will not give them a tax cut or increase economic growth, but it will benefit the rich.

Of course, perhaps the GOP can thread the needle and pass a bill with a bare majority of support in the Senate. There’s nothing that says public opinion has to carry the day.

But, as with the effort to repeal the Affordable Care Act, Republicans in Congress are making it hard for themselves. A bipartisan approach — which is what most successful legislation depends on — would probably lead to more positive news coverage and bipartisan support in the public. As political science research has found, a single dominant message coming from leaders on both sides of the aisle — say, “let’s pass this great tax reform bill” — tends to reduce polarization in the public and build a broader base of support.

As Warshaw pointed out, the GOP strategy is even more puzzling when you consider the kinds of bills that they could be focusing on:

After the passage of the Affordable Care Act, several other political scientists and I found that Democrats in competitive districts who supported the ACA were punished in the 2014 elections — losing almost six points of vote share compared to similar Democrats who opposed the ACA. And the ACA was actually more popular in 2009 than is the Republican tax reform plan now.

Does this mean that pushing unpopular bills will lead to a similar fate for Republicans in 2018? We certainly don’t know. But as Warshaw says, we’re about to test the hypothesis that you can buck public opinion only for so long.