CANONSBURG, PA - MARCH 14: Conor Lamb, Democratic congressional candidate for Pennsylvania's 18th district, speaks to supporters at an election night rally March 14, 2018 in Canonsburg, Pennsylvania. Lamb claimed victory against Republican candidate Rick Saccone, but many news outlets report the race as too close to call. (Photo by Drew Angerer/Getty Images)
Drew Angerer/Getty Images
CANONSBURG, PA - MARCH 14: Conor Lamb, Democratic congressional candidate for Pennsylvania's 18th district, speaks to supporters at an election night rally March 14, 2018 in Canonsburg, Pennsylvania. Lamb claimed victory against Republican candidate Rick Saccone, but many news outlets report the race as too close to call. (Photo by Drew Angerer/Getty Images)
Now playing
01:28
Pennsylvania election shakes up 2018 races
senator bill nelson 11132018
CNN
senator bill nelson 11132018
Now playing
02:03
Nelson: Scott should recuse himself
Rep. Marsha Blackburn, R-Tenn., speaks to supporters after she was declared the winner over former Gov. Phil Bredesen in their race for the U.S. Senate Tuesday, Nov. 6, 2018, in Franklin, Tenn. (AP Photo/Mark Humphrey)
Mark Humphrey/AP
Rep. Marsha Blackburn, R-Tenn., speaks to supporters after she was declared the winner over former Gov. Phil Bredesen in their race for the U.S. Senate Tuesday, Nov. 6, 2018, in Franklin, Tenn. (AP Photo/Mark Humphrey)
Now playing
01:26
Meet the Republicans who held onto the Senate (2018)
Democratic congressional candidate Ilhan Omar is greeted by her husband's mother after appearing at her midterm election night party in Minneapolis, Minnesota, U.S. November 6, 2018. REUTERS/Eric Miller
Eric Miller/Reuters
Democratic congressional candidate Ilhan Omar is greeted by her husband's mother after appearing at her midterm election night party in Minneapolis, Minnesota, U.S. November 6, 2018. REUTERS/Eric Miller
Now playing
01:33
Minorities, LGBT make history in 2018 midterms
WJLA
Now playing
02:01
Hear from the Democrats who took back the House
CNN
Now playing
01:50
Abrams vows to remain in gubernatorial race
Spectrum News NY1
Now playing
02:05
Ocasio-Cortez: This is a movement for justice
KXAN
Now playing
02:07
O'Rourke congratulates Cruz on his victory
CNN
Now playing
01:57
Tapper: This is not a blue wave
CNN
Now playing
02:11
Van Jones: It's a rainbow wave
LAS VEGAS, NV - OCTOBER 20:  U.S. Rep. and U.S. Senate candidate Jacky Rosen (D-NV) speaks during a rally at the Culinary Workers Union Hall Local 226 featuring former U.S. Vice President Joe Biden on October 20, 2018 in Las Vegas, Nevada. Early voting for the midterm elections in Nevada begins today. (Photo by Ethan Miller/Getty Images)
Ethan Miller/Getty Images
LAS VEGAS, NV - OCTOBER 20: U.S. Rep. and U.S. Senate candidate Jacky Rosen (D-NV) speaks during a rally at the Culinary Workers Union Hall Local 226 featuring former U.S. Vice President Joe Biden on October 20, 2018 in Las Vegas, Nevada. Early voting for the midterm elections in Nevada begins today. (Photo by Ethan Miller/Getty Images)
Now playing
01:45
CNN projects Jacky Rosen elected to US Senate
Additional Embargo:   Additional Source(s):    Date Shot: 11/6/2018   Shipping/Billing Info:     Description: Projects: None  Cost Center: Atlanta National Desk / 20100101   Created By: DHackett  On: 1541544461  --------------------------------------------------------------------------------
WSB;
Additional Embargo: Additional Source(s): Date Shot: 11/6/2018 Shipping/Billing Info: Description: Projects: None Cost Center: Atlanta National Desk / 20100101 Created By: DHackett On: 1541544461 --------------------------------------------------------------------------------
Now playing
00:59
Brian Kemp: Confident victory is near
2018 Elections Primary Clean path
CNN
2018 Elections Primary Clean path
Now playing
01:49
Pelosi: Tomorrow will be a new day in America
CNN
Now playing
01:36
The Democrats who might lead the House
CNN
Now playing
01:54
DeSantis thanks Trump in victory speech
KXAN
Now playing
01:44
Cruz: This election was a battle of ideas
(CNN) —  

The Democratic advantage on the generic congressional ballot has tightened to 6 percentage points, a new CNN poll conducted by SSRS finds.

The poll finds that 50% of registered voters say they prefer a Democrat in their congressional district, while 44% say they want a Republican. That’s a major shift in favor of the GOP since February, when Democrats held a 16-point edge. It’s much closer to January, when their lead was just 5 points.

But Democratic voters are much more enthusiastic about casting ballots in November’s midterm elections.

About half – 51% – of Democrats and Democratic-leaning independents say they are extremely or very enthusiastic about voting for Congress in November, compared with just 36% among Republicans and Republican-leaning independents.

And at the same time, those voters who are deeply enthusiastic about voting give Democrats a better than 20-point lead on the generic ballot: 60% prefer the Democrat in their district, while 38% who prefer the Republican.

Overall, just 18% of voters approve of Congress, while 75% disapprove. And an even smaller share of those enthusiastic to vote in the fall, 11%, approve of the way Congress is handling its job.

Though Republicans control Congress, voters say they believe Democrats would do a better job of dealing with a host of key issues.

Among them: Health care (56% Democrats to 36% Republicans, a sharp change from 2010 when the two parties were nearly even on the issue following passage of the Affordable Care Act), the Russia investigation (51% Democrats to 35% Republicans), immigration (51% Democrats to 40% Republicans) and gun policy (48% Democrats to 40% Republicans).

The GOP is favored on just one issue: National security, at 48% to 40% Democrats.

The public is split over whether they prefer the Democrats or the Republicans in Congress on the economy (45% choose each party) and the federal budget (43% prefer the Democrats and 42% the Republicans).

The findings come just two weeks after Democrats won a stunning victory in a special congressional election west of Pittsburgh, where Conor Lamb – fueled in part by energized labor unions – narrowly defeated Republican Rick Saccone in a district President Donald Trump won by 20 percentage points in 2016.

The poll showed that Trump’s approval rating has ticked up to 42% – the highest since the 100-day mark of his presidency.

The CNN poll was conducted by SRSS on March 22-25 among a random national sample of 1,014 respondents, including 913 registered voters, reached on landlines or cell phones by a live interviewer. Results for the full sample have a margin of sampling error of plus or minus 3.7 percentage points. For registered voters, the margin of error is 3.8 points.

CNN’s Jennifer Agiesta contributed to this report.