[2] Nielsen established himself as a traditional tough-on-crime conservative who championed the cause for lower taxes, controlled government spending and gun rights for law-abiding citizens.

[citation needed] Nielsen was narrowly unseated by Democrat Mike Thompson, an aide to then Assemblywoman Jackie Speier.

A question of residency eligibility arose during his bid for the Assembly in 2008, because Nielsen owns 2 homes, one in the district he represents and one near the capitol.

Nielsen won the case and even received a judgment for court costs in the amount of $7,400 against Plaintiff Don Bird.

After reviewing the case, the Attorney General issued a letter on December 22, 2008, stating there was no evidence to warrant further investigation and the matter was closed.