Katie Britt’s Republican response to Joe Biden’s State of the Union address drew reactions ranging from the baffled to the satirical to the appalled, even among fellow rightwingers.

“What the hell am I watching right now?” an unnamed Trump adviser told Rolling Stone.

“It’s one of our biggest disasters ever,” another unnamed Republican strategist told the Daily Beast.

Delivering the official State of the Union response can be a thankless task, as the former Louisiana governor Bobby Jindal and the Florida senator Marco Rubio, deliverers of previously panned speeches, would ruefully attest.

Nonetheless, the 42-year-old Alabama senator is a rising Republican star, widely respected on Capitol Hill and her selection to respond to Biden was a golden opportunity to introduce herself to the wider American electorate.

In his address Biden used his bully pulpit effectively, attacking Republicans in a fiery speech and inviting a strong response. But Britt’s speech, delivered with overt theatricality, oscillating in tone between the wholesome and the wholly horrific, did not land well even in her own party.

Charlie Kirk, founder of the far-right Turning Point USA youth group, said: “I’m sure Katie Britt is a sweet mom and person, but this speech is not what we need. Joe Biden just declared war on the American right and Katie Britt is talking like she’s hosting a cooking show, whispering about how Democrats ‘dont get it’.”

That pointed to widespread confusion over the setting for such a figure to give such an important speech: a kitchen.

As a Gallup poll showed 57% of American voters think the US would be better off if more women were in elected office, Alyssa Farah Griffin, a Trump aide turned never-Trumper, said: “Senator Katie Britt is a very impressive person … I do not understand the decision to put her in a KITCHEN for one of the most important speeches she’s ever given.”

Speaking to CNN, Griffin added: “The staging of this was bizarre to me. Women can be both wives and mothers and also stateswomen, so to put her in a kitchen, not at a podium or in the Senate chamber where she was elected after running a hard-fought race, I think fell very flat and was completely confusing to some women watching it.”

Allie Beth Stuckey, host of the Relatable podcast, which “analyses culture, news and politics from a biblical perspective”, said: “Ok, GOP. Never again. I know y’all were going for the relatable mom speaking in her kitchen from her heart, but it didn’t work. Just a straight, strong speech will do in the future. Thanks.”

Kirk asked followers if they liked the speech. Blue-ticked conservative verdicts included “Man, it was so disappointing”, “No, very babysitter-reading-a-bedtime story-like”, “way too dramatic”, and “the up and down emotion was bizarre”.

Among satirical responses, Tom Nichols, an anti-Trump conservative columnist, spoke for many when he said: “There is no way that this Katie Britt address does not end up as part of the Saturday Night Live cold open.”

Elsewhere, the gonzo filmmaker Tom Arnold said: “Katie Britt is so bad she couldn’t be in one of my movies.”

Julia Ioffe, Washington correspondent for Puck News, said: “Imagine you’re sleeping over at a friend’s house and you get up in the middle of the night to pee and you hear a weird sound so you follow it to the kitchen, where your friend’s mom is drunk, crying, and rambling about the national debt. Those are the vibes from Katie Britt right now.”

From the other side of the political spectrum, however, the gun control advocate Shannon Watts highlighted a darker side to Britt’s performance, as expressed in a particularly lurid passage.

With wavering voice, the senator described meeting a migrant woman who she said described being “sex trafficked by the cartels starting at the age of 12” and who, Britt said, spoke of being repeatedly raped “on a mattress in a shoebox of a room”.

Watts said: “Senator Katie Britt says sexual assault is the worst thing that can happen to a woman while encouraging Americans to vote for a convicted sexual predator.”

Last month, Donald Trump, the presumptive Republican nominee for president, was ordered to pay $83.3m in a civil defamation case arising from a rape allegation a judge said was “substantially true”. Accused of sexual assault or misconduct by more than 20 other women, Trump also faces trial this month on 34 charges arising from hush-money payments to an adult film star who claimed an affair.

Britt endorsed Trump last December.