The good news for Republicans is that President Trump's approval rating has, on balance, ticked up from 38 percent to 40 percent since January as attention has shifted from unpopular GOP proposals on healthcare and taxes to the economy, tariffs and Stormy Daniels. Commensurately, Democrats' lead on the question of which party voters would support for Congress has shrunk from a dozen points in January to about eight points today.

The bad news for Republicans, of course, is that Trump's approval rating is still 40 percent and that they still trail Democrats on the generic ballot by eight points. That's enough to offset the GOP's edge from favorably drawn districts and endanger their 23-seat majority (by our estimate, Democrats would need to win seven to eight percent more votes for House to win 218 of 435 seats).

Moreover, in a reversal from the 2014 midterms, Democrats enjoy a wide voter enthusiasm gap. According to a new CNN/SSRS survey, 51 percent of Democrats and Democratic-leaners said they were "extremely" or "very" enthusiastic about voting in November compared to 36 percent of Republicans/GOP leaners. Young voters, Trump's weakest age segment, also express far more interest in casting ballots than they did four years ago.

This enthusiasm gap has been on display in off-year and special elections all cycle, including last month in Pennsylvania's 18th CD, where Democrat Conor Lamb won a district Trump had carried by over 19 points. Despite two personal visits from Trump and a robust field program orchestrated by the GOP-aligned Congressional Leadership Fund, turnout as a share of 2016 was still seven points higher in Democratic-leaning Allegheny County than it was in GOP-leaning Westmoreland County.

Retirements are also aiding House Democrats' path to a majority. There are 36 districts where Republicans not running for reelection in 2016, including 12 at serious risk of falling to Democrats (Lean Republican or more vulnerable). Only 18 Democrats are exiting, and just four represent seats at serious risk of falling to the GOP. Additionally, Democrats are competitive in an August 7 special election in Ohio's 12th CD to replace GOP Rep. Pat Tiberi, who resigned in January.

If Democrats pick up at least eight Republican open seats (and today, eight of the 36 are leaning their way), they'll already be a third of the way to the 23 they need for a majority. Beyond those, there are 18 Republican incumbents in the Toss Up column and another 20 in the Lean Republican column —- including five in California, three in Texas and three in Virginia. Private partisan polling continues to show most GOP incumbents in much weaker positions than last cycle — even in districts Trump won.

Pennsylvania's new court-ordered congressional map was another blow to Republicans. Under the old lines, Democrats already had a good chance to add two to four seats from the Keystone State; now they have a chance to pick up four to six seats versus 2016.

Republicans desperately need to catch some breaks to offset the new Pennsylvania map. One way they could negate those gains would be to "shut out" Democrats in one or several top-two primaries on June 5 in California. There's a slight chance crowded fields of Democrats in the 39th, 48th and 49th CDs could allow two GOP candidates to advance to the November general election, removing otherwise highly vulnerable GOP seats from the playing field entirely.

Primaries have already proven difficult for Democrats to control: some of their most highly touted, widely endorsed candidates are falling flat with actual primary voters. Kelly Mazeski (IL-06), Alex Triantaphyllis (TX-07), Jay Hulings (TX-23) and Ed Meier (TX-32) all raised more money than their opponents but lost their primaries to candidates with stronger grassroots appeal. And only two of 50 states have held their primaries so far, guaranteeing more surprises to come.

In this difficult environment, the NRCC and the Congressional Leadership Fund have no choice but to run against Nancy Pelosi and seek to individually disqualify Democratic nominees with negative ads over the summer and early fall — before those nominees can introduce themselves — in order to hold onto their majority. But ironically, neither Ryan nor Pelosi are sure bets to remain as their party's leaders come January 2019, no matter which party comes out on top.

Our latest ratings feature 55 competitive seats (Toss Up or Lean Democratic/Republican), including 50 currently held by Republicans and five held by Democrats. There are also three non-competitive seats poised to switch parties thanks to Pennsylvania's new map (PA-05 and PA-06 to Democrats, PA-14 to Republicans). Overall, Democrats would need to win 27 of the 55 competitive races to win a majority. We continue to view Democrats the slight favorites for House control.

Subscribers can read the Bottom Lines for these ratings changes here.

Full List of Changes:

CA-21: Valadao (R)

Likely R to Lean R

IA-02: Loebsack (D)

Likely D to Solid D

NV-03: OPEN (Rosen) (D)

Toss Up to Lean D

NV-04: OPEN (Kihuen) (D)

Lean D to Likely D

NJ-03: Tom MacArthur (R)

Likely R to Lean R

NJ-05: Josh Gottheimer (D)

Lean D to Likely D

NY-18: Sean Patrick Maloney (D)

Likely D to Solid D

NC-09: Robert Pittenger (R)

Likely R to Lean R

OH-10: Mike Turner (R)

Solid R to Likely R

WA-03: Jaime Herrera Beutler (R)

Solid R to Likely R

WA-05: Cathy McMorris Rodgers (R)

Likely R to Lean R

WI-07: Sean Duffy (R)

Solid R to Likely R