Simpkins first attempted to enter politics in 2004, contesting the seat of Cowan at the 2004 federal election for the Liberal Party against veteran Labor incumbent Graham Edwards. He was defeated by Edwards, but received an unexpectedly strong vote, receiving an 8.2% primary vote swing towards him, with the result being unclear for several days. Edwards retired at the 2007 election, and Simpkins won the seat against new Labor candidate Liz Prime with a 2.5% swing, one of only four pro-Coalition swings in Australia and one of only two new House seats won by the Liberal Party. He was re-elected with a 4.75% swing against former Lord Mayor of PerthChas Hopkins at the 2010 election, and again with a slight swing against at the 2013 election. On 6 February 2015 Simpkins announced that he would move a motion, at a meeting of the party room, for a spill of the federal Liberal Party's leadership positions. Simpkins stated that such a motion would give Liberal members of parliament and senators the opportunity to either endorse the Prime Minister, Tony Abbott or "seek a new direction." The meeting was held on 9 February 2015 and the spill motion was defeated 61 votes to 39. At the 2016 election, Simpkins suffered a 5.20% swing against him and was defeated by Labor candidate Anne Aly. During the election campaign, Liberal Justice MinisterMichael Keenan was accused of starting a smear campaign against Aly. Simpkins joined in the campaign targeting Aly for her previous work in counter-terrorism, despite having written to her, in 2015 before she was a Labor candidate, to convey his admiration for her work including the "content of your media interviews and approach to the threat of radicalisation".
Political views
Simpkins is an outspoken social conservative. He was one of six Liberal MPs to leave the house in protest to the apology to the Stolen Generations. Simpkins declared that he worried "that it could lock in negativity about the future", that indigenous people were no longer denied employment opportunities, and that he would "again back children being taken in this situation". He has attacked halal food, declaring in 2011 that "by having Australians unwittingly eating Halal food, then we are all one step down the path of conversion, and that is a step we should only make with full knowledge and not be imposed upon us unknowingly." His position was criticised by Labor MP Chris Bowen. Simpkins has supported banning the burqa in Australia. He has also supported sleep deprivation torture as a means of gaining information, and he opposes same-sex marriage.