There's a reason so few Republicans are talking about tax bill this election year.

Once seen as the Republican Party’s savior for the midterm cycle, the GOP’s historic tax bill — a giveaway to billionaires and corporations — continues to be an electoral albatross.

Any hope Republicans may have had that this year’s April tax season would improve voters’ opinion of the scam bill was dashed in a new poll that finds voters now oppose the corporate giveaway by even larger margins.

The percentage of people who oppose the bill now hits 50 percent, compared to just 41 percent who approve. Six weeks ago, Americans were evenly split on the bill, according to the Greenberg Quinlan Rosner Research poll, which was commissioned by the Democratic Congressional Campaign Committee.

Incredibly, while many voters believe the economy is improving, that’s not translating into a big advantage for the Republican Party, even though they control Congress and the White House. Instead, voters are evenly divided between which party they trust more to handle jobs and the economy.

Voters strongly believe that Republicans in Congress are more likely to “enrich themselves and their friends at the expense of taxpayers,” by a 14-point margin, according to the poll.

There have already been lots of indications that not only is the tax bill failing to buoy GOP chances ing November, it might actually be sinking them.

Republicans had to pull tax ads during the Pennsylvania House special election in March because they found the message in the working-class district wasn’t connecting.

And previously, Republicans ditched the tax cuts message during the Virginia gubernatorial election because the topic simply wasn’t resonating.

The GOP lost both elections.

Meanwhile, “The most vulnerable Republican incumbents in the tightest congressional races in the November elections are talking less and less about the tax cuts on Twitter and Facebook, on their campaign and congressional websites and in digital ads, the vital tools of a modern election campaign,” Reuters reported last month.

And for Republicans in especially tough re-election races, the pro-tax rhetoric has plunged more than 70 percent.

With the tax bill cratering, Republicans are left scrambling for a back-up November message. Some are turning to the past, obsessing over Hillary Clinton and running against her again, instead of touting the party’s tax bill fiasco.

Obviously, if the GOP tax bill had been a roaring success and completely changed the dynamics of the midterm cycle, Republican Speaker of the House, Paul Ryan, wouldn’t be quitting next year.

But he is. And the latest polling confirms why.