WASHINGTON — For more than a decade, House Speaker Nancy Pelosi has exerted a tremendous amount of influence and control over her Democratic caucus.

But she’s now facing arguably her toughest challenge yet, with some House Democrats — fueled by recent developments — demanding to begin impeachment proceedings against President Trump that Pelosi opposes for now.

“During a weekly Democratic leadership meeting in Pelosi’s office on Capitol Hill, Reps. Jamie Raskin, D-Md., David Cicilline, D-R.I., and Joe Neguse, D-Colo., all argued for launching an impeachment inquiry if former White House counsel Don McGahn failed to testify at a planned hearing Tuesday before the Judiciary Committee,” per NBC’s Heidi Przbyla, Alex Moe and Rebecca Shabad.

“It was a big debate and was long and very emotional,” one source inside the Democratic leadership told NBC.

“This isn’t about politics at all. It’s about patriotism. It’s about the strength we need to have to see things through,” Pelosi responded to her Democratic critics, according to Politico.

But just consider all of the news over the last 24 hours that’s emboldening House Democrats:

Trump directed former White House counsel Don McGahn to defy a congressional subpoena and not testify Tuesday.

Former Trump lawyer/fixer Michael Cohen told a closed-door House panel that Trump lawyer Jay Sekulow encouraged him to falsely claim that negotiations to build a Trump Tower in Moscow ended in January 2016, per the Washington Post.

And a federal judge yesterday ruled in favor of the House Oversight Committee's bid to obtain Trump's financial records from his accounting firm.

Oh, and let’s not forget Rep. Justin Amash’s, R-Mich., tweetstorm from over the weekend that Trump engaged in impeachable conduct, or Tom Steyer’s TV ad arguing that the president has been running circles around House Democrats.

“[Trump's] defying you. He’s laughing at you. And he’s getting away with it,” the ad goes.

Bottom line: Pelosi is facing a potential breaking point, as more and more Democrats want to run through a door that the speaker has tried to keep closed – at least for now.

How does she stop this? Does she take control of the process? Or does she get run over?

Bluegrass State of mind

Before there was Donald Trump, there was Matt Bevin — a controversial conservative who shocked the polls and political world when he won Kentucky’s gubernatorial election in 2015.

And today brings us the Democratic primary for the right to challenge Bevin in the fall for his re-election, featuring state Attorney General Andy Beshear (son of former Democratic Gov. Steve Beshear), former state Auditor Adam Edelen and House Minority Leader Rocky Adkins.

Beshear’s the favorite on the Dem side, but Edelen has been outspending him over the airwaves (see below), and he’s gone negative, which has forced Beshear to respond.

The wild card is Adkins, who could benefit from the Edelen-versus-Beshear fight.

Bevin, who’s facing his own primary challenge today from underdog Republicans, is relatively unpopular and thus vulnerable in the fall. But incumbency, a low unemployment rate and the state’s rural-versus-urban divide could help him.

Sounds like another Republican we know…

2020 Vision: Trump continues to elevate Joe Biden

Campaigning in Pennsylvania last night, President Trump talked a lot about Joe Biden.

“Don't forget Biden deserted you. He's not from Pennsylvania. I guess he was born here but he left you, folks. He left you for another state. Remember that, please,” Trump said.

(For the record, Biden moved from Pennsylvania to nearby Delaware when he was a boy.)

More Trump: “The previous administration what they did to our country, they should be ashamed of themselves. [Applause] Sleepy Joe said that he’s running, to quote save the world, well he was, he’s going to save every country but ours. And remember he said a week ago, China is not a competitor. China is not a competitor.”

And here was Trump on Biden’s crowd size at his recent campaign launch in Philadelphia: “It’s no wonder that when Joe Biden announced he’s running for president, by the way, by the way, by the way, we have thousands of people, so... Now they said he had 600 people. No, not very good. Not very good. I’d say 150. And that was on an announcement, right? I’d say 150 people.”

(For the record, Biden’s crowd size was estimated at around 6,000.)

On the campaign trail today

Beto O’Rourke remains in Iowa, hitting a town hall in Tipton before attending his CNN town hall in Des Moines at 10:00 pm ET... And Bill Weld participates in a Kennedy Institute Conversation in Boston.

The Lid: Pennsylvania polka

Don’t miss the pod from yesterday, when we looked at Trump’s potential troubles in Biden’s backyard of Pennsylvania.

Data Download: The number of the day is … $6 million

$6 million.

That’s the amount of money that’s been spent on TV and radio ads so far in the 2019 race for Kentucky governor, according to Advertising Analytics.

The biggest overall spender has been Adam Edelen’s campaign at $2.1 million, while a pro-Edelen Super PAC has kicked in an additional $1 million.

Edelen’s Democratic rival, Andy Beshear, has spent $1.3 million over the airwaves.

And incumbent Republican Gov. Matt Bevin has spent $480,000.

Total ad spending

Adam Edelen campaign (D): $2.1 million

Andy Beshear campaign (D): $1.3 million

Kentuckians for a Better Future (pro-Edelen Super PAC): $1.0 million

Rocky Adkins campaign (D): $911,000

Matt Bevin campaign (R): $480,000

Robert Goforth campaign (R): $234,000

Putting Kentucky First (pro-Bevin Super PAC): $94,000

Ike Lawrence campaign (R): $24,000

Tweet of the day

.@NBCNews and @MSNBC have announced the 2020 presidential election campaign "embeds" -- the journalists who will be deployed throughout the country to report on all aspects of the 2020 presidential election.



You can follow them via this list: https://t.co/w8Oi2UCz7k pic.twitter.com/AoiJSZQ9MA — NBC Politics (@NBCPolitics) May 20, 2019

ICYMI: New clips you shouldn’t miss

The backup border funding plan for DHS would take millions from TSA and other agencies, NBC’s Julia Ainsley reports.

Black voters aren’t forgetting past broken promises as they weigh their choices for 2020, writes the Washington Post.

Kris Kobach has submitted a list of conditions — including 24/7 access to a government jet — if he becomes the country’s “immigration czar.”

Don’t miss POLITICO’s Stephen Shepard on what professional pollsters are saying about trends in the industry as a huge presidential election approaches.

And Alabama Public Television refused to air an episode of children’s program “Arthur” that included a same-sex marriage.

Trump agenda: GOP vs. Justin Amash

Republicans are trying to figure out what to do after one of their own, Justin Amash, said the president has engaged in “impeachable conduct.”

The Washington Post writes on Trump’s tendency to make himself a central character in every story — political or otherwise.

A new report finds that Betsy DeVos used her personal email in “limited” circumstances.

A federal judge is denying Trump’s bid to block his financial records from Congress.

2020: Hey, big spender

Trump is outspending all of his Democratic rivals on Facebook.

Here’s what we learned from Trump’s appearance in Biden’s backyard last night.

The RNC outraised the DNC in April.

Bernie Sanders is trying to make a pitch to black voters in the Deep South.

Beto O’Rourke says he’d do a Fox News town hall.

It’s special election day in Pennsylvania.

And here’s what to watch for on primary day in Kentucky.