Rep. Tim Ryan (Ohio), whose message never caught on and who failed to make the past two debates, dropped out of the Democratic primary contest on Thursday, following Rep. Eric Swalwell (Calif.), Rep. Seth Moulton (Mass.), Sen. Kirsten Gillibrand (D-N.Y.), Washington Gov. Jay Inslee and former Colorado governor John Hickenlooper. Former housing and urban development secretary Julián Castro has said he’ll drop out if he doesn’t raise $800,000 by Halloween.

Meanwhile, thanks to a national Quinnipiac University poll, on Thursday, Sen. Amy Klobuchar (Minn.) qualified for the Nov. 20 debate with a fourth poll showing her at a minimum of 3 percent support. Her campaign touted the news: “Since Amy’s stand-out performance in the October debate we’ve raised more than $2 million and seen a surge in interest and engagement across the country,” the campaign said in a written statement. “We will use this momentum to continue building on our strong grassroots operation as we head into Iowa and New Hampshire.” Interestingly, for someone who has clearly focused intently on Iowa, she is not neglecting New Hampshire, which follows a week after the Iowa caucuses. Her success will depend on her finish in the latter.

Speaking of Iowa, an online Iowa State-Civiqs poll has Sen. Elizabeth Warren (Mass.) in first with 28 percent, and South Bend, Ind., Mayor Pete Buttigieg (who, like Klobuchar, has focused on Iowa) surprisingly comes in second with 20 percent, followed by Sen. Bernie Sanders (I-Vt.) at 18 percent and former vice president Joe Biden at 12 percent. Klobuchar is next at 4 percent, and Sen. Kamala D. Harris (Calif.) draws 3 percent.

With every caveat about early polling, there has been movement in Iowa. The RealClearPolitics average has Warren at 22.5 percent, Biden at 18.8, Buttigieg at 15.8 and Sanders at 15.3. According to Iowa and DNC rules, only those who get at least 15 percent collect delegates. In other words, these candidates are all tightly bunched.

So far, the debate next month will include Biden, Sanders, Warren, Buttigieg, Harris, Klobuchar, Tom Steyer, Andrew Yang and Sen. Cory Booker (N.J.), a manageable group in which the majority of those onstage have a reasonable path to the nomination. Interestingly, most of the candidates will fill the “center-left” description. (As of now, former congressman Beto O’Rourke has not qualified. If he remains on the outside, that could put him in the also-running category with people such as Castro.)

There are more questions than answers at this stage. Has Biden stabilized? If he falters, will Buttigieg, who has taken a moderate stance on health care and foreign policy, rise to the challenge and attract a mix of moderates and progressives? Will Warren negate the impression from the last debate that she was hiding the ball by producing a concrete funding mechanism for Medicare-for-all? Can a strong finish in Iowa boost Klobuchar into the top tier?

From all this, we should underscore three points. First, a candidate who has risen in the polls and then fallen precipitously has a hard time persuading voters to rethink her or him. It is not impossible (see John McCain in 2008), but it is a heavy lift.

Second, if impeachment proceeds to a Senate trial that lasts for weeks, Warren, Harris, Sanders, Klobuchar and Booker will be among those tied up inside the Beltway. That is a legitimate concern when others (e.g., Biden, Buttigieg) will be free to roam Iowa and New Hampshire. (Warren has said she can do both but she cannot physically be in D.C. six days a week without detracting from her time on the stump.)

Finally, Trump faces almost certain impeachment and trial in the coming months. He is virtually assured the nomination of his party — unless support collapses, unless the devastating depositions behind closed doors push public opinion dramatically and Republicans do not figure out they would be far better off with Vice President Pence as the incumbent instead of the unraveling, damaged president. A non-Trump nominee or a Trump nominee who is severely damaged (beyond what he is now), presents a new issue for Democrats: Who is most “electable” in the event Trump is removed, resigns or gets a strong primary challenger to submarine his reelection prospects?

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