A month ago Republicans passed what was, according to some measures, the most unpopular bill in decades: their tax plan.

Today, it’s looking more and more as if that was a risk well worth taking.

A day after President Trump played up the tax cuts in his State of the Union address, a Monmouth poll showed a huge swing in favor of the bill. Although 26 percent of Americans approved of the package in mid-December, as lawmakers were putting the final touches on it, support in the latest poll rose to 44 percent. For a bill that sometimes polled with twice as many opponents as supporters, it’s now on level terms, with just as many supporters as opponents (44 percent).

Other polls have shown smaller bumps in the plan’s popularity — a Washington Post-ABC News poll a couple of weeks back, for instance, showed support rising to 34 percent — but none until Wednesday had shown the law as drawing level. So it’s possible the Monmouth poll is an outlier.

But there are plenty of positive signs here for Republicans. And there are reasons to believe things could get better.

Unlike other polls, for instance, Monmouth’s question about the tax plan doesn’t tie it to Republicans or to Trump. That suggests partisanship and Trump fatigue may have depressed support while it was the subject of intense debate, and that people might warm to it as they judge it more on its merits.

And speaking of those merits, there’s something important about all these polls that we need to keep in mind: People still don’t seem to recognize how the tax cuts will benefit them personally. Polls have routinely shown more people expect to see their taxes increase rather than decrease, but that’s simply not what will happen — at least not for many years. The Monmouth poll, for instance, shows the law drawing even on popularity while 24 percent believe their own taxes will go down.

President Trump praised the state of the U.S. economy during his first State of the Union speech on Jan. 30. (The Washington Post)

We’re just now entering February, which is when people’s paychecks will start getting slightly bigger as their withholding changes to reflect the new tax laws. Republicans seem to be counting on Americans seeing that extra money in order for the law to become even more popular. Which isn’t a bad bet. If people are expecting their taxes to go up (36 percent) or even stay the same (32 percent) and taxes go down, that should be a pleasant surprise and could fuel more support for the bill.

The question, as Politico has noted, is whether people will recognize the changes when they’re dispersed over two dozen biweekly paychecks. For middle- and lower-income Americans, for instance, that might be $20 or $30 per paycheck, and it could even be offset by other changes, like rising health insurance premiums or changes in benefits. In contrast, the George W. Bush tax cuts of 2001 delivered instant rebate checks across the country.

The most immediate and noticeable impact of the GOP’s tax plan has been that millions of people who have received one-time bonuses (many of them $1,000) that companies handed out after the bill passed. But that’s still a very small portion of the American electorate — a poll this week showed 2 percent said they had benefited from the law already — and there seems to be only room for improvement when it comes to people’s perceptions of how the law affects them.

Which brings us back to the Monmouth poll. Perhaps an even bigger finding for the GOP — and one likely related to improving views of the tax plan — is a huge shrinking of the generic ballot, on which Republicans have trailed by double digits in many recent polls. The poll shows it closer than any other recent poll, with Democrats ahead by 2 points — 47-45 — so again, it could be an outlier. But it’s not the first poll conducted since the law’s passage to suggest that the Democrats’ big advantage has narrowed; several have shown the Democrats’ generic-ballot lead down to the single digits.

There is plenty that will play out before the 2018 election is held in 10 months, but for a Republican Party that seemed on a course for disaster, passing a severely unpopular piece of legislation may just turn out to be a good move.