She was nominated at the top spot on the Centre Party ballot in Nord-Trøndelag for the 2013 election, which is considered a safe seat.

[10] Following the 2021 election, she joined party leader Trygve Slagsvold Vedum with pre-government negotiations in Hurdal Municipality that began on 23 September.

[11] When the Centre Party withdrew from government on 30 January 2025, Arnstad confirmed that they would continue to support Jonas Gahr Støre as prime minister.

She left the post on 17 March 2000 when the government resigned over the issue of gas power stations, and was succeeded by Olav Akselsen.

Elmsäter-Svärd stressed the importance of continued transport over the border, but didn't comment on the case Arnstad was referring to.

[16] In October, Arnstad expressed that the new Follo rail line would be a demanding project after the cost of it increased to 23,5 billion NOK.

Arnstad took this action after VG reported that the Norwegian Labour and Welfare Administration (NAV) had ordered around 2700 disabled people to park the bikes they had been given by them.

[19] In late February, she promised improvements to soil protection, and said it would be a central part in the then upcoming National Transportation Plan that would be presented in autumn.

When confronted with the tweet, Arnstad added that she had only meant to express that it was nice to be back home in Trøndelag, and stated that she loved Oslo, but that at the time she didn't want to be there at work.