Here is the big, year-end question for Democrats:

Is the anger at President Trump that carried them to big wins in the 2017 off-year elections strong enough to make them even bigger winners in the 2018 midterms?

The party’s leaders don’t buy it.

House Minority Leader Nancy Pelosi, D-Calif., spent last week throwing cold water on excited calls from fellow Democrats to impeach the president.

And Senate Minority Leader Charles Schumer, D-N.Y., echoed that line, telling a reporter that talk of impeachment is “premature… you might blow your shot when it has a better chance of happening.”

That makes sense.

But the grassroots energy inside the party — from moderates to left-wingers — is all about taking the fight to Trump to the point of impeachment.

A late October poll by Public Policy Polling, a Democratic-leaning firm, found a “record level of support for impeaching Donald Trump,” with 49 percent calling for impeachment and 41 percent opposed.

That near-majority call reveals the deep split between the Democrats’ youthful, activist base and the party’s cautious, old guard, led by senior congressional leaders.

Both sides want to win in 2018. But in the run-up to next year’s election, it is the party’s establishment leaders who are losing the intraparty fight to restrain growing excitement at the prospect of impeaching Trump.

Both sides want to win in 2018. But in the run-up to next year’s election, it is the party’s establishment leaders who are losing the intraparty fight to restrain growing excitement at the prospect of impeaching Trump.

Rep. Maxine Waters, D-Calif., recently ended a speech at Glamour’s Women of the Year Awards with a robust chant: “Impeach Him!”

Billionaire Tom Steyer, the party’s biggest donor in recent years, is running a multi-million dollar ad blitz that has led 1.5 million people to sign a petition calling for the president’s impeachment.

The advertisement says, “People in Congress and his own administration know that this president is a clear and present danger who is mentally unstable and armed with nuclear weapons.”

Pelosi, when pressed on the Steyer advertisement, said impeachment “is not someplace I think we should go.” Similarly, Schumer reacted to Steyer by saying, “I’m not against him doing it but I think it is premature.”

Tom Perez, the chairman of the Democratic National Committee (DNC), has joined the congressional leadership in withholding support for impeachment. He told ABC’s Martha Raddatz flatly, “I am not talking about impeachment.”

Rep. Keith Ellison, D-Minn., the DNC’s deputy chairman, told the Atlantic that the Republicans present a major hurdle to successful impeachment, given their majorities in both the House and the Senate.

“I think that he totally deserves to be impeached, but given the present composition of Congress, it’s not about to happen soon,” Ellison said, “so why not focus on things that are right in front of us.”

These establishment strategists also point out that the last time Democrats aimed their fire at Trump’s often erratic behavior, they were not successful.

Presidential candidate Hillary Clinton made the case that Trump’s words and actions should disqualify him as a presidential candidate. Obviously, it did not work.

Now political insiders argue it will be more fruitful for the Democrats to wait on the findings of Special Counsel Robert Mueller’s investigation into ties between the Trump camp and Russia before jumping on the impeachment bandwagon.

Without clear evidence of high crimes and misdemeanors, the start of impeachment hearings could create a backlash, as some voters rally to his side.

Another point to consider is fundraising.

At the moment, Federal Election Commission filings show the Republican National Committee having raised $93 million through August, with $47 million in cash available.

Democrats are nowhere near that sum. For all the big wins for Democrats this year and the talk of grassroots energy growing on the Democratic side, the party has raised far less than the GOP — $46 million through August with $6.8 million in cash on hand.

Top Democrats favor focusing on positive messaging — more jobs and better health care — aimed at increasing donor confidence.

But pragmatic strategies from the Democrats’ congressional leadership have not stopped calls for impeachment from growing inside the party.

In a revealing split with party leaders, six House Democrats announced proposed articles of impeachment against President Trump.

“We have taken this action because of great concern for our country and our Constitution, our national security and our democracy,” Tennessee Democrat Steve Cohen said last week.

Rep. Brad Sherman, D-Calif., introduced articles of impeachment against Trump in July. He has told The New York Times his action was “speaking for and galvanizing those people who are appalled at the [president’s] recklessness and the incompetency.”

Two leading grassroots groups, Democracy for America and MoveOn.org, are pushing for immediate impeachment. They can push all they like. At the moment, the Republican majority in Congress is sure to block them.

The Democrats are heady with momentum on their side as the 2018 midterms begin. But political momentum can fade. That is a big danger heading into midterms where the Democrats often fail to turn out.

That’s why Pelosi, Schumer and Perez are wrong not to at least wink at the activists calling for impeachment. It comes at no cost and it energizes the base.