We didn't have to wait long after Donald Trump's proposal to temporarily ban Muslim immigrants before another politician said something else off-color about the world's fastest-growing religion.

This time, though, it was a Democrat who stepped into politically fraught territory. And in doing so, Rep. Loretta Sanchez (D-Calif.) could complicate the line her party hopes to draw between Trump, xenophobia and the rest of the Republican Party.

Sanchez, who is running for the open U.S. Senate seat in her state, suggested Wednesday that up to 20 percent of Muslims want to establish an Islamic caliphate and are willing to use terrorism to get there.

"We know that there is a small group, and we don’t know how big that is — it can be anywhere between 5 and 20 percent, from the people that I speak to — that Islam is their religion and who have a desire for a caliphate and to institute that in any way possible," Sanchez said on "PoliticKING with Larry King."

Later on in the interview, Sanchez goes so far as to use the "t" word, saying this group of Muslims "is willing to use and they do use terrorism."

This isn't the first time Sanchez has stepped in it when it comes to cultural matters. In May, she let out a Native American war cry while speaking to a group of Indian Americans. A few days later, she apologized.

Her spokesperson stressed to Politico that Sanchez was making clear it's unknown how many Muslims might be sympathetic to groups like the Islamic State, which is aiming to build such a caliphate. Sanchez issued a statement to BuzzFeed, which first reported her comments, saying "I strongly support the Muslim community in America and believe that the overwhelming majority of Muslims do not support terrorism or ISIS."

But in even attempting to categorize how many Muslims might support the use of terrorism, Sanchez stepped on to a slippery and arguably irresponsible slope, both politically and in her responsibilities as an elected official.

Politically, the Democrat's words certainly don't help her party make the case that Republicans are the ones trying to stoke xenophobia and undermine the United States' basic tenet of religious freedom. (Worth noting here: Sanchez is the highest-ranking woman on both the House Armed Services and House Homeland Security committees.)

It also gives one more advantage to Sanchez's main Democratic primary challenger for the seat being vacated Sen. Barbara Boxer (D-Calif.). Attorney General Kamala Harris's campaign is probably just tacking this line on to a ready-to-go attack ad featuring some of Sanchez's more eyebrow-raising comments. (The Sacramento Bee reported that, in 2010, while facing a Republican opponent who immigrated from Vietnam, Sanchez told Spanish-language TV that she thought the Vietnamese community was teaming up with Republicans to take her out.)

Most troublesome, though, is the possibility that Sanchez's theory gives people who want to take her argument further -- like banning all Muslim immigrants from America, or heaping suspicion and even threats of violence on to the ones who are already here -- license to do so.

It's a small step from the congresswoman's words to considering it fair game to question the allegiance of any Muslim, since according to a lawmaker who purports to know such things, one-fifth of Muslims might sympathize the aims and even methods of the Islamic State. That is not an argument Sanchez, her party, or most any politician wants to facilitate.

Sure, what Sanchez said might blow over and become yet another minor political controversy for her and a footnote in the greater struggle about how the West should react after terrorist attacks like those in Paris and San Bernardino, Calif. But it was terribly off-message.

And that's reason enough for Sanchez to serve as a warning for any other politician who is tempted to try to categorize members of an entire religion in these divided times: Stop and think about what you're saying first. Then, probably don't say it.