The events in Washington D.C. are certainly not helping Merz's chances for CDU leader either.
Merz is seen as a Trump-like extremist/hardliner of some sort within the CDU and among CDU members, which might have been somewhat popular in the past years.
But considering the events, the CDU delegates might now opt for Laschet or Röttgen as a more de-escalating alternative ...
I strongly doubt that there are any delegates who will change their vote from Merz to Laschet/Röttgen simply because of the capitol riots.
Few would for *just* that reason, perhaps - but it maybe creates a somewhat worse climate for him?