President Donald Trump demonstrated his dominance over the Republican Party this week, serving notice to GOP lawmakers that they risk the wrath of their base by going against him.

On Tuesday, South Carolina Republicans ousted a veteran lawmaker whose primary opponent called him disloyal to the president, and GOP voters in Democratic-leaning Virginia selected a firebrand with a Trump-like affinity for culture wars as their U.S. Senate candidate. In Congress, a GOP senator who is retiring accused his colleagues of being too afraid to "poke the bear" by taking on Trump's protectionist trade policies.

"We are the party of President Donald J. Trump," South Carolina Republican Katie Arrington said after her upset victory over Rep. Mark Sanford in a House primary contest.