The House on Thursday narrowly approved $1.9 billion to fortify the Capitol after the Jan. 6 insurrection, as Democrats pushed past Republican opposition to try to harden the complex with retractable fencing and a quick-response force following the most violent domestic attack on Congress in history.

The bill’s 213-212 passage came a day after the House approved the formation of an independent commission to investigate the deadly mob siege by President Donald Trump’s supporters, who battled police to storm the building in a failed attempt to overturn Democrat Joe Biden’s election.

The two measures now face an uncertain outcome in the evenly divided Senate as most Republicans have objected to both — and as some liberal Democrats opposed the security money over concerns about policing. Three Democrats voted against the spending bill and three voted “present” as House Speaker Nancy Pelosi and other Democratic leaders lobbied their own members during the vote to ensure passage.

The legislation to form the commission passed much more easily on Wednesday, with 35 Republicans joining all Democrats to vote for it. Still, Senate Democrats could have trouble persuading enough Republicans to vote with them after Senate Republican Leader Mitch McConnell announced he would oppose the inquiry.

Democrats grew frustrated during the debate on both bills, charging that Republicans are looking away from the insurrection that they witnessed themselves out of fealty to Trump.