Under current law, the maximum child tax credit is $2,000, which will revert to $1,000 after 2025 without action from Congress. Both House and Senate proposals would increase the top credit, but phase-ins would mirror the current tax break.

WASHINGTON — Nearly six months after Joe Biden left the White House, Senate Republicans are still scrutinizing his presidency, kicking off the first in what’s expected to be a series of congressional hearings this year on his mental fitness in office.