Capitol goes into lockdown as Trump supporters breach barriers and clash with law enforcement while Congress debates election challenges

• The US Capitol went into lockdown Wednesday as throngs of President Donald Trump's supporters breached barriers around the building and clashed with Capitol Police.
• The clashes came as Congress convened to officially certify the results of the 2020 general election.
• The process is typically pro forma, but it's in the spotlight this year given Trump's groundless assertion that Congress and Vice President Mike Pence have the power to throw out some states' electoral votes based on unsubstantiated claims of fraud.
• The president spoke at a "March for Trump" rally shortly before Congress convened, and video footage showed Trump's supporters breaching barriers around the Capitol building and attempting to occupy it.

The US Capitol went into lockdown on Wednesday after throngs of President Donald Trump's supporters breached multiple barriers, clashed with law enforcement officers, and tried to storm the Capitol building on Wednesday as Congress met to certify the results of the 2020 general election.

"All buildings within the Capitol Complex, Capitol: External security threat, no entry or exit is permitted, stay away from exterior windows, doors. If outside, seek cover," Capitol police said in message.

The certification process is typically pro forma and doesn't draw much, if any, national attention. But it's in the spotlight this year given Trump's groundless assertion that Congress and Vice President Mike Pence can unilaterally throw out the electoral votes of states based on the president's unsubstantiated claims of widespread voter and election fraud.

—Jake Sherman (@JakeSherman) January 6, 2021

Shortly before the violence erupted, thousands of pro-Trump demonstrators came to the nation's capital to attend a "March for Trump" to protest Congress' certification of the electoral votes. The president spoke at the rally, and as Congress convened, both the Madison and Cannon buildings on the Capitol Complex were evacuated, according to reporters on the scene.

Read more: Secret Service experts are speculating in group chats about how Trump might be hauled out of the White House if he won't budge on Inauguration Day

Punchbowl News' Jake Sherman reported that staffers in the Cannon building "are being told to take escape hoods, and to go underground to tunnels."

Videos posted on Twitter also showed Trump supporters charging toward Capitol Police as the officers tried to fend them off while Congress debated the first of several election challenges from Trump's allies.

CNN's Jake Tapper tweeted that a House Republican staffer told him Capitol Police were also evacuating private residences on Capitol Hill.

Several lawmakers, along with reporters in the Capitol, said that the scene has them shaken.

—ELIJAH SCHAFFER (@ElijahSchaffer) January 6, 2021

—Alayna Treene (@alaynatreene) January 6, 2021

—Alayna Treene (@alaynatreene) January 6, 2021

—Rep. Nancy Mace (@RepNancyMace) January 6, 2021

—Rep. Haley Stevens (@RepHaleyStevens) January 6, 2021

—Igor Bobic (@igorbobic) January 6, 2021

—Steven Nelson (@stevennelson10) January 6, 2021