The Cook Political Report today will shift its 2018 forecast for 20 House districts — all in favor of Democrats.

“Not only did dozens of Republicans in marginal districts just hitch their names to an unpopular piece of legislation, Democrats just received their best candidate recruitment tool yet.”

“Democrats aren’t so much recruiting candidates as they are overwhelmed by a deluge of eager newcomers, including doctors and veterans in traditionally red seats who have no political record for the GOP to attack — almost a mirror image of 2010.”

Key statistic: Of the 23 Republican lawmakers from districts won by Hillary Clinton in 2016, 14 voted for the GOP health care bill.

Ron Brownstein: “President Trump’s historically low approval ratings provide Democrats legitimate reasons for optimism about their prospects in the 2018 elections, especially in the House. But that confidence rests on a contradiction: Minorities and Millennials, the groups most alienated from Trump, are traditionally the constituencies least likely to vote in midterm elections.”

“That dynamic helped fuel the GOP sweeps in both the 2010 and 2014 contests under former President Obama, and offers a warning for the next one.”

“The challenge is especially urgent for Democrats because Trump divides younger and older Americans so sharply. Though Trump showed strength among blue-collar white Millennials, he carried just 36 percent of young people overall last November.”

Amy Walter: “Think of the GOP as a body and Trump like a donated organ. Trump is not organic to the GOP, but the body has accepted it as its own.”

“However, solid and continued support for Trump isn’t the whole story. The question is whether this support for Trump is going to translate into turn-out and support for the GOP in 2018. You don’t have to go too far back in history to find an example of a president who came to office with backing from a new, enthusiastic group of voters, only to find that those voters failed to consistently show up for the party. The so-called Obama coalition never soured on Obama, but they also didn’t show up to vote for his party in 2010, 2014 or 2016 – i.e., the years he wasn’t on the ballot.”

National Journal: “Instead of veering to the right-as many red-state Democrats have tried with little success in recent years-2018’s most endangered senators have repeatedly voted against Trump’s Cabinet nominees, helped filibuster his Supreme Court pick, and ratcheted up their rhetoric against policies they say hurt the middle class. While these senators still need to win back plenty of Trump voters ahead of the midterms, strategists say the moves reflect a new reality for red-state Democrats. After three election cycles of dormancy, the Democratic base could suddenly play a significant role in their reelections, even in states Trump won handily.”

A new CNN/ORC poll finds 50% of American voters would vote for the Democratic candidate for Congress while 41% would choose the Republican candidate if the election were held today.

“A lead that large, this far out, is not necessarily predictive, however — although it approaches the edge Democrats held early on in the 2006 election cycle when they won control of the House, it is also similar to their advantage early on in the 2010 cycle, which ended with a Republican takeover of the chamber.”

“A wave of first-time candidates eager to fight President Trump and his young administration plan to challenge House Republican incumbents, giving Democratic Party leaders hope that they can capi­tal­ize on the anger and intensity at grass-roots protests and town hall meetings across the country this year,” the Washington Post reports.

“At least 15 declared candidates or contenders on the verge of announcing have emerged in districts that Democrats must win to take back the House, including in several districts where the party did not seriously compete in 2014 or 2016, according to party officials.”

A new Public Policy Polling survey finds Democrats lead the generic congressional ballot by 47% to 41%.

“But what’s more notable is the enthusiasm imbalance. 63% of Democrats say they’re ‘very excited’ about voting in the 2018 election, compared to only 52% of Republicans who express that sentiment. When you look at the 2018 House picture just among the voters most excited about turning out next year, the lead for Democrats grows to 19 points at 57-38. Republican leaning voters are comparatively disengaged, with the GOP holding advantages only among voters who are ‘somewhat excited’ (48-40) and ‘not that excited’ (46-31).”

Sabato’s Crystal Ball: “Those looking for electoral drama in the 2018 cycle should pay attention to the 38 gubernatorial races being held this year and next. In our initial ratings of these contests, more than half of them — 20 of 38 — start in the competitive Toss-up or Leans Republican/Democratic categories. That includes a whopping 10 Toss-ups: five of those are currently controlled by Republicans, four by Democrats, and one by an independent (Bill Walker of Alaska).”

“Contributing to this slew of competitive ratings is the fact that so many of the governorships contested over the next year and a half are open: At least roughly half of them will not feature an incumbent, and an additional three (Alabama, Iowa, and South Carolina) will or are likely to feature an unelected incumbent seeking a first elected term.”