Complex sentence: Ståhlberg did not seek re-election in 1925, finding his difficult term of office a great strain, and believing that the right-wing and the monarchists would become more reconciled to the republic if he stepped down.
Split into simpler sentences: Ståhlberg did not seek re-election in 1925, finding his difficult term of office a great strain. He also believed that the right-wing and the monarchists would become more reconciled to the republic if he stepped down.