Updated

Brief doesn't begin to describe Rep. Stephanie Herseth's (search) political honeymoon.

In the space of less than 36 hours, the South Dakota Democrat narrowly won her seat in Congress, flew to Washington to take the oath of office, made her first speech on the House floor and cast her first vote.

And she was sharply attacked by Republicans eager to dethrone her in November.

"It's sad to say but with her very first vote, we see Stephanie is more concerned with appeasing the liberals who got her elected than delivering needed help for South Dakotans," said Carl Forti, a spokesman for the GOP campaign committee.

"Larry Diedrich and his friends are trying to distort Stephanie's record before the ink is dry," shot back Russ Levsen, Herseth's spokesman, referring to the Republican she defeated in the election. "You'd think they'd give South Dakotans a break from the negative political attacks, but instead they are back at it just hours after she was sworn in."

For her part, the 33-year-old lawmaker sought to strike a less political note as she began her congressional career.

Moments after being sworn into office in the House chamber, she said she was "humbled by this moment and by the trust and responsibility that South Dakota has placed on me." In remarks that lasted only a few minutes, she thanked Speaker Dennis Hastert (search) (a Republican) for promptly swearing her in; South Dakota's senators (both Democrats) for their help; her grandparents; and Jeff Trandahl, a South Dakotan who is clerk of the GOP-controlled House.

She also took note of the "tragedy" that led to her election — former GOP Rep. Bill Janklow's (search) resignation, which followed his conviction of manslaughter for his involvement in a fatal traffic accident.

A few hours after he spoke, Herseth returned to the House floor and cast her vote against administration-backed legislation that would give eligible unemployed workers up to $3,000 for use on job training and other services that might help them find work.

The measure passed 213-203 over the opposition of most Democrats, who argued it did little to address larger unemployment problems.

Diedrich, who lost to Herseth by fewer than 3,000 votes on Tuesday, is her opponent for the fall campaign, as well.