Complex sentence: After they gained control of the House in 2011, Republicans sought successfully to cut the Obama Administration's funding requests for diplomatic security by hundreds of millions of dollars; nevertheless, the Republicans claimed that they voted for money to ensure the safety of diplomatic staff overseas.
Split into simpler sentences: After they gained control of the House in 2011, Republicans sought successfully to cut the Obama Administration's funding requests for diplomatic security by hundreds of millions of dollars. Nevertheless, Republicans claimed that they voted for money to ensure the safety of diplomatic staff overseas.