US Democrats are to mount an extensive investigation of what went wrong in the 2014 and 2010 elections, hoping to find ways to translate success in presidential campaigns into future mid-term contests.
The party will form a committee in the coming weeks to conduct a "top-to-bottom assessment" of its performance in recent mid-term elections and try to determine why they have struggled to turn out its core voters in non-presidential elections.
"It's apparent that there are increasingly two separate electorates: a mid-term electorate and a presidential electorate. We win one and we don't seem to be able to win the other," said Florida congresswoman Debbie Wasserman Schultz, who leads the Democratic National Committee.
"That is a fundamental dynamic that we have to change."
Reflecting voters' discontent with President Barack Obama, Democrats suffered heavy losses in last week's elections, ceding Senate control to the Republicans and surrendering more seats in the Republican-majority House of Representatives.
Republicans picked up governor's offices in a number of Democratic-leaning states like Massachusetts, Maryland and Illinois and strengthened their grip on state legislatures.
Democrats have been successful in turning out an Obama-led coalition of minorities, women and young voters in presidential elections, but have struggled in midterm races when turnout is lower and the electorate tends to be older and whiter, favouring Republicans.
Ms Wasserman Schultz said the new committee, whose membership will be announced in the coming weeks, would look at the party's tactics, messaging, get-out-the-vote operations and digital efforts in recent non-presidential elections. The group plans to report back in February.
Republican National Committee spokeswoman Kirsten Kukowski said last week's elections underscored her party's momentum.
"When Republicans came to the table and played their game, they lost and that's a problem," she said. "We have said from the beginning that Obama 2012 wasn't the standard for us. The mid-terms showed that and we are going to keep building on our successes."
The Democratic National Committee's post-election review has parallels to a post-mortem examination that Republicans conducted after Mitt Romney was defeated by Mr Obama in the 2012 presidential election.
The report urged Republicans to shift their focus to year-round, on-the-ground political organising in the states and recommended that Republicans embrace a comprehensive immigration overhaul. That recommendation quickly hit resistance from congressional Republicans who rely on primary voters who oppose creating a path to citizenship for immigrants living illegally in the US.
"Our party has a problem," Ms Wasserman Schultz said in a video announcing the project. "We know we're right on the issues. The American people believe in the causes we're fighting for. But the electoral success we have when our presidential nominee is able to make a case to the country as a whole, doesn't translate in other elections. That's why we lost in 2010, and it's why we lost on Tuesday."
Ms Wasserman Schultz said she discussed the need for a review with Mr Obama on election night and both agreed on the need to move forward. She also spoke about her plans with Rep Nancy Pelosi of California and Senator Harry Reid of Nevada, the party's leaders in Congress.
"We need to understand everything that went wrong so that we can address all the potential problems and prepare for future elections," she said.