With his refusal to concede defeat and his determination to isolate G.O.P. leaders who criticize him, the former president has effectively denied Republicans from engaging in the sort of reckoning that parties traditionally undertake after they lose power.

Even with Democrats controlling Congress and the White House for the first time in over a decade, many of the Republicans who spoke at the conference here said strikingly little about President Biden or the nearly $2 trillion stimulus measure the House passed early Saturday, which congressional Republicans uniformly opposed…

The attention surrounding Mr. Trump and his potential plans for the future are forestalling a focused attack on Mr. Biden and the Democratic-controlled Congress.

Senator Ted Cruz of Texas, who used his speech on Friday to hail Mr. Trump’s leadership of the party, said in a brief interview that his party’s voters would pivot to the present once Mr. Biden’s agenda became more clear.