Less than eight months before Election Day, the midterm landscape is still taking shape. It’s still not clear whether Democrats will have a good night (and potentially fall short of a majority) or a historic night in the House that puts them well over the top. But mounting evidence nationally and at the district level points to a Democratic advantage in a growing number of seats.

Democratic prospects improved in a handful of seats in Pennsylvania, thanks to a new, court-ordered map. And the party’s successes in state and local elections over the last 14 months demonstrate a surge in Democratic voters, particularly in blue areas, that could be problematic for Republican candidates in the fall. GOP incumbents in districts Hillary Clinton carried in 2016 might be particularly susceptible to increased Democratic enthusiasm.

Ratings for each House and Senate race are detailed in Roll Call’s Election Guide, while the specific ratings changes are listed below. As a reminder, the ratings aren’t set in stone and will necessarily adjust as the races and cycle progress.

We have shifted the Inside Elections ratings in 15 races toward the Democrats.

• AZ-02 (Open — Martha McSally, R) From Tossup to Tilts Democratic
• CA-10 (Jeff Denham, R) From Leans Republican to Tilts Republican
• CA-25 (Steve Knight, R) From Leans Republican to Tilts Republican
• CA-45 (Mimi Walters, R) From Likely Republican to Leans Republican
• FL-07 (Stephanie Murphy, D) From Tilts Democratic to Leans Democratic
• IL-06 (Peter Roskam, R) From Likely Republican to Leans Republican
• IA-01 (Rod Blum, R) From Leans Republican to Tilts Republican
• MI-11 (Open — Dave Trott, R) From Leans Republican to Tilts Republican
• NC-13 (Ted Budd, R) From Solid Republican to Likely Republican
• NH-01 (Open — Carol Shea Porter, D) From Toss-up to Tilts Democratic
• NJ-02 (Open — Frank A. LoBiondo, R) From Leans Republican to Toss-up
• NJ-05 (Josh Gottheimer, D) From Toss-up to Tilts Democratic
• NJ-07 (Leonard Lance, R) From Likely Republican to Leans Republican
• WA-05 (Cathy McMorris Rodgers, R) From Solid Republican to Likely Republican
• WI-03 (Ron Kind, D) From Likely Democratic to Solid Democratic

And in one race shifts toward the Republicans.

• WA-08 (Open — Dave Reichert, R) From Tilts Democratic to Toss-up

You can read analyses of these races and over 100 others in the Feb. 16 issue of Inside Elections.