Speaker of the House Nancy Pelosi administers the oath of office Thursday to U.S. Rep. Kendra Horn, D-Oklahoma City, during a ceremonial swearing-in on Capitol Hill in Washington. [AP Photo]

The speaker vote occurred before a swearing-in ceremony for Horn and others. The NRCC's rapid response confirms that national Republican groups consider the freshman congresswoman to be beatable in two years.

“BREAKING: Democrats like Kendra Horn are once again ignoring your voice by voting for Nancy Pelosi as Speaker. Fight back NOW,” the text said, with a link to the NRCC's fundraising page.

After Horn, an Oklahoma City Democrat, voted for Nancy Pelosi to be speaker of the House that afternoon, the National Republican Congressional Committee sent text messages to its 5th District supporters.

"Right after the November elections, they probably had a list of their top targets for 2020 and Oklahoma's 5th is definitely going to be on that list," said Michael Crespin, director of the Carl Albert Congressional Research and Studies Center at the University of Oklahoma.

Horn's surprising victory over former Rep. Steve Russell — the first for a 5th District Democrat in 44 years — prompted immediate questions about who would challenge her in 2020 and whether she can hold what has, for so long, been a Republican seat.

Horn's campaign sent its first fundraising email of the 2020 race on Dec. 13, three weeks before she was sworn-in to office for the first time. The email noted that political forecasters consider the 5th District race to be a toss-up in 2020.

“We defied the odds and made history on November 6th, but if we don't start getting ready for 2020, we could lose everything,” her campaign wrote in the email. “If we come up short in 2020, Oklahomans will lose a critical voice in Washington and we take a huge step backwards on issues like health care, a fair economy and education.”