ESSEN, Germany (Reuters) – German Chancellor Angela Merkel won re-election as chairwoman of her Christian Democrats (CDU) on Tuesday with 89.5 percent of votes cast by just under 1,000 party delegates, giving her a boost as she seeks a fourth term in office next year.

The endorsement fell short of the 96.7 percent Merkel won when she was last re-elected two years ago. Her decision last year to open Germany’s doors to some 1 million migrants sapped some grassroots support and has dented the CDU’s poll ratings.

Merkel’s lowest winning score in election as chairwoman was 88.4 percent in 2004. The CDU is meeting in Essen, where Merkel was first elected party chairwoman in 2000.

(Writing by Paul Carrel; Editing by Michael Nienaber)