The Note: Blue wave sweeps over New Jersey and Virginia, but watch for the undertow

— -- The TAKE with Rick Klein

Democrats can breathe again. But taking a breath is a questionable proposition in the Trump era.

It's hard to overstate what Tuesday's sweeping victories mean for Democratic enthusiasm and excitement. The party that needed a win got a bunch of them with a night that replenishes the bench and rejuvenates the faithful.

The victories in Virginia and New Jersey were repudiations of Trumpism, in part, because all politics are national these days. A surge of minority, liberal and college-educated voters came out in force for Democratic candidates.

The forces of political gravity do apply to President Donald Trump after all – whatever ownership of candidacies he chooses to take. Any honest analysis has to point out, though, that this could mean any number of things for 2018 and beyond.

Ralph Northam, a physician who is now Virginia's governor-elect, ran as a "healer." Last night began to heal some Democratic wounds.

Yet, this is an era of political waves.

Democrats are peeking above water again.

Waves, however, wash in both directions.

The RUNDOWN with MARYALICE PARKS

The focus last night quickly shifted from big gubernatorial races to action further down the ballots.

Here's why:

First, Democrats beat expectations. In Virginia, they flipped at least 13 seats and put Republicans' control of the state's House of Delegates in play. Several of the state races are still too close to call. Democrats say it was the largest pickup for their party in the state since 1899.

Around the country, it looked like a pattern, with mayoral wins in North Carolina and state legislature seats flipping in New Hampshire, Washington and New Jersey.

Second, Democrats also landed some symbolic victories, sending two Latinas and an Asian-American woman to the Virginia statehouse for the first time, as well as a transgender woman.

Seattle elected its first lesbian mayor and openly gay school board member.

A Sikh American man was elected mayor of Hoboken, N.J.

And an African-American transgender woman was elected to the Minneapolis city council.

For a party that's been in a slump, those local stories could boost morale on a national level and potentially suggest a backlash against Trump-era rhetoric on race and culture.

Third, 2020. Not the presidential, but redistricting.

After the 2020 census, statehouses will redraw the congressional map, and if Democrats learned anything from Republicans' last go-around it's that controlling local governments can have big payouts for this reason alone.

Last, some solid blue regions turned a deeper shade of navy, and there Democrats will see no reason to hold back. Having played defense during the first year of Trump's presidency, Democratic strongholds will likely shift to the offensive and put some policy meat on their liberal bones.

In Washington, Oregon and California, Democrats now completely control the state government.

A blue wall out west could pass sweeping climate change legislation and significant universal health care or gun control bills.

In Maine, voters last night chose to expand Medicaid, perhaps an interesting harbinger of trends to come.

The TIP with JOHN VERHOVEK

After they take office, Sheila Oliver and Justin Fairfax will be the only two African-American Democratic lieutenant governors in the country.

Fairfax, 38, is the first African-American to win a statewide office in Virginia since 1989, when Douglas Wilder won the governor's office.

As the winner of the lieutenant governor's race, Fairfax will now be seen as a rising star in the Democratic Party and an immediate contender for the governor's mansion in 2021. Governors can serve only one term in Virginia under state law.

WHAT YOU NEED TO KNOW TODAY:

QUOTE OF THE DAY

"We won because I am a transgender woman ... because of my inherent identifiers, not despite them. I never ran away from them. I championed them." -- Danica Roem, first openly transgender person elected to serve in a U.S. state legislature.

NEED TO READ

The Note is a daily ABC News feature that highlights the key political moments of the day ahead. Please check back tomorrow for the latest.