Voters interviewed ahead of the vote said they were looking for local leaders who could build major new infrastructure, stimulate the economy or help particular groups such as youth.
In the Saturday elections, the DPP lost seven of its 13 cities and counties to main opposition Nationalist Party or Kuomintang (KMT).
On May 24, 2017, Taiwan's Constitutional Court ruled that the Civil Code's current definition of marriage - between a man and a woman - was unconstitutional.
LGBT couples hope Taiwan will be the first place in Asia to recognize same-sex marriage, letting them share child custody and insurance benefits. "Family values and inclusion of those values in the education of the next generation are mainstream public opinion that the government should heed".
Amnesty tweeted, "Taiwan's referendum results rejecting marriage equality are a bitter blow but despite this setback, we remain confident that love and equality will ultimately prevail!"
Last year, Taiwan's highest court ruled that same-sex couples had the right to legally marry and set a two-year deadline for legalization.More news: Man shoots woman to death in Ocala Walmart, still at large
"She will need to express clearly that Taiwan is happy to bolster cooperation with the USA, while she also needs to make it clear that Taiwan is not trying to lock horns with China" said Jou Yi-cheng, who was once a speechwriter for former President Chen Shui-bian, a DPP member.
Tsai told reporters that she would take "complete responsibility" for the defeat as she resigned as chair of the party.
Relations between the two countries deteriorated after Tsai's pro-independence party entered office in 2016. Wins in the southern city of Kaohsiung, which had been held by the DPP for 20 years, and Taichung were significant.
The KMT won 15 of 22 mayoral and county magistrates seats, up from just six.More news: Mitchell Starc replaces injured Billy Stanlake for third T20I
Since her election, Tsai has walked a fine line on relations with China, maintaining Taiwan's de facto independent status that the vast majority of Taiwanese support, while avoiding calls from the more radical elements of her party for moves to declare formal separation from the mainland.
"The election shows that the Tsai administration has betrayed Taiwan's interests and become a troublemaker whose actions have drifted farther away from the practical needs of the Taiwan people and the historical truth of the consensus there is only one China".
Tensions have also increased between China and Taiwan in recent months, after China conducted numerous military drills in the Taiwan Strait and has successively stolen a number of Taiwan's dwindling diplomatic allies, including El Salvador.
Ms Tsai said the DPP would reflect on the defeat, but she vowed to press on. Beijing has denied the allegations. As in previous elections it also tried to fuel fears about China.More news: Jerome Corsi: rightwing author pursuing plea deal with Robert Mueller
As for public sentiment regarding Taiwan's relations with China, Taiwanese online media Up Media, in an opinion article published on November 25, pointed out that neither DPP nor KMT candidates mentioned at length their positions with regard to their China policy, indicating that there is a consensus among the general Taiwanese public that unification with China isn't an option.