“What has failed in the past is to reverse engineer public policy from a poll, and we didn’t do that this time,” Sen. Brian Schatz (D-Hawaii), seen here in a file photo, said of his party’s platform for the midterms. (Melina Mara/The Washington Post)

In 2006, Democrats unveiled their new agenda less than four months before the midterm elections. In 1994 and 2010, Republicans did not release their platforms until just a few weeks before those pivotal midterms.

In all three elections the House majority changed hands, and two of them also flipped the Senate majority. But today’s Democrats have decided to move much faster than those other successful parties out of power, unveiling the first portions of their “Better Deal” agenda last week in Virginia.

Democrats, after analyzing their miserable 2016 showing, found voters didn’t know where the party stood on key economic issues. Starting now, they want to build an economic identity so that their candidates can run next year on something more than just opposition to President Trump. That continued Tuesday as Senate Minority Leader Charles E. Schumer (D-N.Y.) unveiled the latest plank — proposed taxes and penalties on corporations that ship jobs overseas.

The pressure point, however, is crafting an agenda that balances the needs of energizing anti-Trump liberal activists without driving away centrist voters and Republicans disillusioned with the president and the lack of results coming from the GOP-led Congress.

Democrats’ success requires the party to win big among independents and a critical share of Republican voters, particularly in defending five Senate seats in states that Trump won by at least 19 percentage points last year.

These Senate races do not fit into the normal debate that comes after losing a national campaign, where the losing side considers whether its candidate should have appealed more to the center or revved up the party’s base.

Without winning a significant bloc of Republican voters in next year’s Senate races, Democrats will fall deeper into the minority and find it difficult to win back the majority in 2020.

It’s a little better in the House, where Democrats need a net gain of 24 seats for the majority and there are 23 districts held by Republicans that Trump lost in 2016. But most of those seats are held by tough-to-beat incumbents with their own local brand.

So the Democratic path to the House majority requires big gains in several dozen districts that supported Trump by at least a small margin.

This formula played out six weeks ago when Democrats came up short in courting enough right-leaning voters in the special election for a House seat in Atlanta’s suburbs.

“We needed to find more Democrats and the math got difficult,” John Anzalone, pollster for the Democratic candidate, Jon Ossoff, told consultants on an after-action call arranged by the Democratic Congressional Campaign Committee.

“We needed to peel off Republicans,” Anzalone said, according to the notes from a consultant on the call.

To be sure, that Georgia district has a bigger GOP tilt than the first 30 or 40 seats that Democrats are targeting next year. The Ossoff campaign served up a rough formula for Democrats in those more fertile districts: match his winning share of independent voters, get almost 10 percent of GOP voters and then hope the base turns out enough to carry them to victory.

That’s no easy task, even with a historically unpopular president.

And Democrats have to do that while defending a dozen of their own districts that actually supported Trump. Rep. Cheri Bustos (D) won her western Illinois district by more than 20 percentage points, easily overcoming Trump’s narrow win there.

Bustos said the key in these Trump-leaning districts will be developing an agenda built around boosting wages to complete the sale with voters who are used to supporting Republicans, moving Democrats beyond the early anti-Trump focus.

“When I ask, what’s on your mind, tell me what you want me to know before I head back out to Washington, not one question or comment about impeachment, not one question or comment about Russia,” Bustos, who helped craft the “Better Deal” proposal, said.

So far, in addition to tough talk on trade, the “Better Deal” calls for regulations to make corporate mergers more difficult, for tougher enforcement to lower costs of prescription drugs and for increased job training. The agenda is anchored around better jobs and lower costs for consumers.

“This is the headline, the fine print will be the policies still to come,” Bustos said.

Anzalone said that Democrats in the top 30 or 40 most contested races should model their campaigns off Ossoff, who ran as a bipartisan problem solver who wanted more tech jobs in the district.

If those Democrats replicate Ossoff’s edge among independents, they will win because these districts have fewer regular Republican voters than the one in Georgia, Anzalone said in an interview Tuesday.

“If you turn those independents, you’ll get enough Republicans, because you’re on message,” he said.

But some liberals found Ossoff’s campaign to be too bland and have been pushing Schumer and House Minority Leader Nancy Pelosi (D-Calif.) to advocate more generous policies such as the free college proposal from Sen. Bernie Sanders (I-Vt.).

That proposal, along with Sanders’s push for a national health-care system for all, were left out of the early agenda items.

Some liberal Democrats claim they are winning the early tug of war, by shunting aside political consultants whose only worry is campaign fallout.

“What has failed in the past is to reverse-engineer public policy from a poll, and we didn’t do that this time,” said Sen. Brian Schatz (D-Hawaii).

The anti-merger policy is in line with what Sanders supports and the crackdown on prescription drug prices is not easy for Democrats from Mid-Atlantic states with a heavy pharmaceutical industry presence. “It didn’t look like last night’s dinner put back in the microwave,” Schatz said.

That scares some Democratic strategists, who predict that Trump’s presidency is its own guarantee to turn out liberal voters. They believe the economic agenda should appeal to those Democrats who supported Trump.

Sens. Claire McCaskill (D-Mo.) and Jon Tester (D-Mont.), facing reelection in states where Trump won by almost 20 percentage points, both cited a pending “Better Deal” proposal for a massive program to promote broadband technology in rural communities as the sort of platform they will discuss in their races.

But each senator made clear they might stray from the “Better Deal” orthodoxy in their states.

“I’m not offended at anything that is contained in there,” McCaskill said. “I may not join the huzzah for all the national Democratic branding. But at least we’re moving toward the stuff that really matters.”

Read more from Paul Kane’s archive, follow him on Twitter or subscribe to his updates on Facebook.