Yes, they were trying to steal the election away from Biden who won. The electoral votes from the 50 states were on a table in the Senate and removed as they removed the Senators. The insurrectionists got into the chamber:
...
The riot was stupid. Each state has backup information on the electoral votes. The mob was never going to succeed.
What did Trump do while the insurrectionist mob committed crimes? Nothing initially.
Three hours into it, he did a video promoting his big lie that he won, saying he loved the rioters but telling them to home.
But there was planning in advance.
see
Insurrection Timeline: Latest Updates
Nov. 10, 2020: Miller embeds
three fierce Trump loyalists as top Defense Department officials: Kash Patel (former aide to Rep. Devin Nunes (R-CA)), retired army Gen. Anthony Tata (
pro-Trump Fox News pundit), and Ezra Cohen-Watnick (
former assistant to Trump’s first national security adviser, Mike Flynn).
At such a late date in Trump’s presidency,
many ask, why the shake-up at the Department of Defense? We may be learning the answer........
As the attack unfolds, Trump is
initially pleased and disregards aides pleading with him to intercede. Sen. Ben Sasse (R-NE)
later says that, according to Trump aides, he is “delighted,” while “walking around the White House confused about why other people on his team [are]n’t as excited.” Trump initially
rebuffs and resists requests to mobilize the National Guard.......
3:29 p.m.: Governor Northam
announces mobilization of Virginia’s National Guard. But there’s a hitch. Federal law requires Defense Department authorization before any state’s National Guard can cross the state border onto federal land in DC. That approval doesn’t come until almost two hours later.
(DoD Memo) 3:47 p.m. Governor Hogan mobilizes his state’s National Guard and 200 state troopers.
The Defense Department “
repeatedly denies” Hogan’s request to deploy the National Guard at the Capitol. As he awaits approval, House Majority Leader Steny Hoyer (D-MD)
calls Hogan from the undisclosed bunker to which he, Speaker Pelosi, and Senate Minority Leader Chuck Schumer (D-NY) have been evacuated. Hoyer pleads for assistance, saying that the Capitol Police is overwhelmed and there is no federal law enforcement presence.
4:17 p.m.: Trump
tweets a video .”
4:18 p.m.: Miller gives voice approval to notifying surrounding states to muster and be prepared to mobilize their National Guard personnel.