Rep. Rod Blum (R-Iowa) walked out of an interview with Iowa station KCRG-TV9 after being asked about taking donations by investigative reporter Josh Scheinblum. (KCRG-TV9)

The footage of Rep. Rod Blum (R-Iowa) walking out of an interview with an Iowa reporter is brutal. And it's going viral for a reason: In trying to protect himself from anger in this health-care debate, Blum just made himself a target of it.

Being defensive (and, in Blum's case, dramatic) is pretty much the opposite of what House Republicans who could be vulnerable for supporting the House health-care bill need to be doing right now.

In the political tinderbox that is much of America right now, one impulsive comment or action — like walking out of a TV interview that hadn't even touched on health care — can light a fire that spreads across the nation.

Let's start with the interview in question. KCRG-TV reporter Josh Scheinblum asks Blum, who voted for the controversial House health-care bill last week, why he's checking people's IDs for a town hall later that night. For several months now, Republican lawmakers across the nation have been flooded with constituents — many but not all of them on the left — angry about the proposed changes to health care.

Blum's response to Scheinblum's question: “I don’t represent all Iowans — I represent the First District of Iowa. That would be like saying, ‘Shouldn’t I be able to, even though I live in Dubuque, be able to go vote in Iowa City during the election because I’d like to vote in that district instead?’”

“Would you still take donations from a Republican in Iowa City?” Scheinblum asks.

Blum smiles a wry smile, throws up his hands and bounces out of his chair. “I'm done here,” he says as his hands reach for his microphone to rip it off. “This is ridiculous. This is ridiculous,” he says as he unravels his microphone and drops it into Scheinblum's hands. “He’s just going to sit here and badger me,” Blum says to the children standing around him, who were supposed to underscore his support for a community center, as he walks away.

The footage really is striking. A GOP lawmaker just off a tough vote gets so frustrated he walks out of an interview he agreed to do, on a week where his main job is to go home and explain why he supported the controversial health-care bill that narrowly passed the House. Cameras captured the whole thing.

And boom, it becomes an instant national story, a microcosm of how conservative Republicans, especially in swingy districts, are struggling to defend why they voted for a bill many of them despise.

Also worth noting: The reporter hadn't even gotten to ask Blum about his health-care vote!

But pre-screened voters at a town hall he held that night sure did.

Blum, a member of the conservative House Freedom Caucus, is torn up about the vote he just took. He opposed the Republicans' first version to revise Obamacare because it didn't do enough to lower premiums.

But he ended up voting for the second version, which outside analysts think will lower premiums for healthy people but raise them drastically for sick and lower-income people.

Democrats targeted Blum in 2016 for the very reason his conservative record doesn't match up with the district's swingyness. Democrats are targeting Blum again — they think if they can flip enough districts like Blum's, the House majority could be in play in the November 2018 midterm elections. (It worked for Republicans in 2010 after Democrats passed health-care reform.)

At his town hall a few hours later, Blum defended his decision to walk out of the interview: “Well, we get there and we were ambushed; they didn't want to do anything on the Dream Center,” Blum said, according to The Washington Post's Ed O'Keefe, who was in Dubuque on Monday for the town hall.

Getting “ambushed” is in the eye of the beholder. But the fact is Republicans like Blum are going to get a lot more tough questions like this. And they need to figure out how to actually answer them.

Tried to get into a town hall for your member of Congress, but couldn't? Share your experience with Post reporter Amber Phillips here.