G.O.P. Opens Mayorkas Impeachment Push With No Evidence of High Crimes

House Republicans on Wednesday kicked off formal impeachment hearings against Alejandro N. Mayorkas, the homeland security secretary, accusing him of willfully failing to enforce immigration laws even as leading constitutional experts said there was no basis to do so.

The G.O.P. drive to impeach Mr. Mayorkas is the latest escalation in the party’s effort to attack the Biden administration on immigration, a politically potent issue that has long animated the hard-right Republican base and has become a liability for President Biden in recent months as migration has surged across the U.S.-Mexico border.

But Republicans have struggled to make the case that their policy complaints are enough to support charges of high crimes and misdemeanors.

On Wednesday, G.O.P. lawmakers accused Mr. Mayorkas of fomenting, or at least exacerbating, a surge in migration and drug trafficking across the southern border by failing to execute the full power of the laws that might mitigate the situation.

“After nearly three years of watching this unfold, what other conclusion is there but that this is an intentional crisis?” Representative Mark E. Green, Republican of Tennessee and the chairman of the Homeland Security Committee, said on Wednesday. He argued that Mr. Mayorkas had implemented “open-border policies” knowing that they would be exploited by dangerous cartels.

Democrats maintained that Republicans were unfairly targeting Mr. Mayorkas for simply carrying out Mr. Biden’s policies, in an attempt to satisfy G.O.P. hard-liners who are clamoring for a border crackdown and have threatened a government shutdown to get their way.