Complex sentence: He and fellow "The New Republic" editor Noam Scheiber claimed the CBO did not include in its estimate various cost-saving provisions intended to reduce health inflation, also positing that the CBO has a history of consistently underestimating the impact of health legislation.
Split into simpler sentences: He and fellow "The New Republic" editor Noam Scheiber further noted the CBO did not include in its estimate various cost-saving provisions intended to reduce health inflation. They also noted the CBO has a history of consistently underestimating the impact of health legislation.