Aldag was elected in the
2015 election as a Member of Parliament for
Cloverdale—Langley City. In the
42nd Canadian Parliament, he was appointed to two parliamentary committees; the
Environment and Sustainable Development committee and the Special Joint Committee on Physician-Assisted Dying, an issue in which he consulted extensively with his constituents. The issue of Physician-Assisted Dying touched him, causing him to be a proponent of families having conversations about their wishes in these situations. The
federal by-election to replace him was scheduled for December 16, 2024 and was won by Jansen. Aldag announced he would resign his seat effective May 27, 2024, to seek the
BC New Democratic Party nomination in
Langley-Abbotsford in the 2024 British Columbia election. He resigned his seat May 31, 2024 and was officially nominated as the NDP candidate in Langley-Abbotsford on July 20, 2024, but lost to
BC Conservatives candidate
Harman Bhangu in the
2024 British Columbia general election. He would later replace Nasima Nastoh as the Liberal candidate in
Langley Township—Fraser Heights before losing in that riding in the
2025 Canadian federal election to Conservative incumbent
Tako van Popta. ==Electoral record==