Taiwan's year-end local elections are turning into a test of both party chairs, and the result will shape President Lai's 2028 reelection odds — bad for whichever side loses ground, but the DPP has more to gain.

• Japanese political scientist Ogasawara Yoshiyuki says both KMT chair Cheng Li-wun and DPP chair Lai Ching-te must lock in their base voters while winning over swing voters, a tricky balance that will decide the outcome.
• The DPP is the "challenger" after its heavy loss last time and started organizing unusually early, forcing early primaries in Tainan, Kaohsiung and Changhua to heal party splits.
• The KMT is the "defending champion," but Cheng is not a local-politics expert and left nominations to faction bargaining, which got messy in Changhua and Hsinchu County.
• Cheng is the most China-friendly KMT chair in memory and already met Xi Jinping, while Lai has had to tone down the "resist China, protect Taiwan" message after the failed mass-recall campaign.
• Swing voters care more about local issues like transport, the economy and an aging population than ideology, so heavy ideological messaging mostly fires up the base without adding votes.

The scorecard: if the DPP only holds its current five counties and cities, the KMT wins big again and Lai's reelection looks shaky. If the DPP adds three or four more, that counts as avoiding disaster. If it also takes New Taipei, that is a "big win" that sharply boosts Lai's 2028 prospects and throws the KMT into internal panic.

Even a bad night likely will not cost Cheng her job: Beijing's Taiwan Affairs Office has bet on her since the Xi meeting and would not want her to resign, so she probably stays on. If the KMT holds New Taipei, calls for Cheng to run for president in 2028 will grow.

Outlook: Watch total national vote share, not just seats — the KMT led by 8.6 points last time, and August polls suggest a slight DPP gain, with plenty of room for surprises in the final two months.