WASHINGTON — With more than 450 days to go until Election Day 2020, many elected Republicans are already eyeing the exits.

So far, we’ve seen 11 House Republicans say they’ll retire or seek another office in 2020. And don’t forget that GOP Sens. Lamar Alexander of Tennessee, Pat Roberts of Kansas and Mike Enzi of Wyoming have already announced that they aren’t running again.

The House exodus includes four GOP members from Texas alone, three of whom won re-election in 2018 by less than a 5-point margin.

The story of these retirements isn’t just that some of them open up pickup opportunities for Democrats, though. It’s that they show just how uncomfortable many rank-and-file Republicans have been in the Trump era.

Retirements are typically a tell about how members view their party’s chances in the next election. And yes, some of these folks are in their late 70s or older. And of course, the no-fun realities of being in the minority have a way of pushing burnt-out members towards the door.

But these retirements also reflect an environment so toxic that even members with safe seats (and potentially promising futures on the Hill) are throwing in the towel.

The buzziest recent retirement was Will Hurd — a Trump critic who was vocally upset about the direction of the party and faced a dicey reelection race.

But what about someone like Texas’ Mike Conaway, a staunch conservative and key member of his state delegation who won reelection with 80 percent of the vote?

With the current relentless news cycles about race and rhetoric — punctuated by the weekend's racially-motivated attack in El Paso — are members really getting any less motivated to call it quits?

And if the political environment is so heated that they think they can’t speak out, the next best thing may be to just up and leave.

It’s not just in the House, either. GOP senators whose seats are up must be asking themselves the same question. Does Susan Collins really want to run for reelection in this environment?

And remember: There’s almost always at least one senator whose retirement is a surprise. Remember Tennessee’s Bob Corker last cycle?

Controversy erupts over public shaming of Trump donors

Speaking of the political environment, Texas Democratic Rep. Joaquin Castro (twin brother of the presidential candidate) is under fire for tweeting the names and employers of some Texas Trump donors and saying they “are fueling a campaign of hate.”

Trump campaign spokesman Tim Murtaugh called the publication of the names “reckless and irresponsible” and “a target list” that endangers the safety of Castro’s constituents.

Meanwhile, Julián Castro’s presidential campaign is defending the candidate’s brother so far, pointing out that the donor information is publicly available.

2020 Vision: Biden, Booker set to address white supremacy and gun violence

As the president heads to El Paso and Dayton today, both Joe Biden and Cory Booker are set to address racism and white supremacy on the trail.

Here’s a sneak peek at what Booker, who’s speaking at Emanuel AME Church in Charleston, is expected to say, per excerpts of his speech: “[T]here is no neutrality in this fight. You are either an agent of justice or you are contributing to the problem. Addressing this isn't an act of charity or philanthropy, it is an issue of national security; it is an issue of patriotism -- it is an issue of love. And we can begin to express that love by changing our laws.”

And here’s what Biden is set to say at an event in Burlington, Iowa: “How far is it from Trump’s saying this 'is an invasion' to the shooter in El Paso declaring 'his attack is a response to the Hispanic invasion of Texas?' Not far at all. How far is it from the white supremacists and Neo-Nazis in Charlottesville – Trump’s 'very fine people' -- chanting 'You will not replace us' – to the shooter at the Tree of Life synagogue in Pittsburgh saying Jews 'were committing genocide to his people?' Not far at all. In both clear language and in code, this president has fanned the flames of white supremacy in this nation."

On the campaign trail today

It’s a crowded day in Iowa: Biden, Warren, Hickenlooper and Gillibrand are all campaigning in the Hawkeye State. And Delaney, Williamson, Yang, Sestak and Klobuchar all attend a Dickinson County Democrats’ event in Storm Lake, IA…. Cory Booker addresses gun violence and white nationalism at Emanuel AME Church in Charleston…. And Steve Bullock also has a speech in D.C. on gun violence.

Dispatches from NBC’s embeds

Sen. Bernie Sanders toured an apartment building in Los Angeles, California that is home to many previously homeless people in the city. NBC’s Gary Grumbach has Sanders’ response to his experience: “It is painful to know we are the wealthiest country on earth and there are people a few feet away from us here who are sleeping out on the street, you know for too long we have ignored this growing crisis and everyone thinks it’s someone else out there until it happens to them until they lose their job or their landlord raises there rent and they suddenly find that they and their kids can’t find affordable housing or suddenly it's not them it's me who’s out on the streets.”

And former Vice President Joe Biden fundraised in Boise, Idaho, where he discussed why he decided to run for president. NBC’s Marianna Sotomayor sends along the pool report from the fundraiser: “He spoke about the three reasons he got into the race for the presidency, citing the riots in Charlottesville, a need to restore the middle class (which he called ‘the backbone of our country’) and to bring the country together. ‘When the middle class does well, the poor have a way up and the wealthy do very well, and in the meantime, we can provide social, political and economic stability.’”

Republicans head to a runoff in Mississippi’s gubernatorial race

Well, this wasn’t the result Lt. Gov. Tate Reeves wanted from yesterday’s primary.

Reeves, long considered the GOP heir apparent in Mississippi’s gubernatorial race, fell just short of the 50 percent required to avoid a runoff against rival Bill Waller Jr. later this month.

And some observers in the state think Reeves might be on the wrong side of the momentum in a two-man race.

One of the key issues in this contest, by the way? Reeves staunchly opposes any type of Medicaid expansion, while Waller backs a version that’s been supported by some GOP lawmakers in other red states.

The winner of the runoff will face Democrat Jim Hood in what’s likely to be a competitive contest in the fall.

Data Download: The number of the day is… 28 percent

28 percent.

That’s the share of Democratic primary debate watchers who said that Elizabeth Warren did the best job, according a new Quinnipiac poll.

That puts her ahead of Biden (15 percent), Sanders (8 percent), Harris (8 percent) and Booker (7 percent).

A plurality — 32 percent — of Democratic primary voters also said that, regardless of how they plan to vote, they think Warren has the best policy ideas.

Warren also saw an uptick in her overall polling against the rest of the Democratic field, up from 15 percent support last month to 21 percent support. She remains in second place overall, while Joe Biden maintains his frontrunner status with the backing of 32 percent of primary voters.

Tweet of the Day

“He was one of my favorites. He was really, as my dad would say, he was a man. Well, you’re not now. He's a boy.”

---Harry Reid on Lindsey Graham to @samstein.https://t.co/SoUhBroBCh — Jon Ralston (@RalstonReports) August 6, 2019

The Lid: Poll check

Don’t miss the pod from yesterday, when we did a deeper dive into that Quinnipiac poll.

ICYMI: News clips you shouldn’t miss

It sure sounds like John Hickenlooper is open to quitting the presidential race in favor of a Senate challenge to Cory Gardner.

Amy Klobuchar is out with a new agriculture and rural America revitalization plan.

NBC’s Leigh Ann Caldwell looks back at Mitch McConnell’s record of opposing gun legislation in the wake of tragedies.

Campaign embeds Priscilla Thompson and Maura Barrett preview the Iowa State fair, which starts Thursday.

Trump Agenda: “Red flag” laws get more traction

Would the death penalty actually be a deterrent to mass shootings?

Republicans are warming to “red flag” gun control bills.

Trump is still heading to the Hamptons for a fundraising trip on Friday.

Peter Strzok is suing the FBI.

The NRA is fighting new calls for gun control amid plenty of internal controversy of its own.

Trump and the RNC are challenging a new California law that would force the president to release his tax returns to get on the state’s ballot.

2020: On the hunt (for a new job?)

Jon Huntsman is resigning from his job as U.S. ambassador to Russia in order to pursue a potential run for governor in Utah.

NBC’s Ben Kamisar and Alex Seitz-Wald explain why the Democratic debates may get bigger before they get smaller.

Mike Gravel is endorsing Bernie Sanders.

The New York Times magazine: “How Bill de Blasio went from progressive hope to punching bag.”