WASHINGTON (AP) — Promoted as needed relief for the middle class, the Senate Republican tax overhaul actually would increase taxes for some 13.8 million moderate-income American households, a nonpartisan analysis showed Monday.

The assessment by Congress' Joint Committee on Taxation emerged as the Senate's tax-writing committee began wading through the measure, working toward the first major revamp of the tax system in some 30 years.

Barging into the carefully calibrated work that House and Senate Republicans have done, President Donald Trump called for a steeper tax cut for wealthy Americans...