Most of the 11 S&P sectors are trading higher, led by financials (+1.9%), telecom services (+1.5%), industrials (+1.4%) and consumer discretionary (+1.3%); on the downside, the tech sector is among the weakest spaces, currently unchanged.
Once the bills are reconciled, the resulting bill could cut corporate tax rates to 20 percent from 35 percent.
In U.S. corporate news, Aetna +1.1% after agreeing to be bought by CVS Health (-4.2%) for $207/share in cash and stock.
"Sentiment still remains that tax reform will get done and we will get a 20 percent tax rate, and that will boost earnings significantly", said Lindsey Bell, an investment strategist at CFRA Research.
All three major indexes moved sharply lower late in the session.
In earnings, AutoZone posted stronger-than-expected earnings, sending its stock higher.
Elsewhere in corporate news, Bloomberg reported that Bank of America plans to buy back an added $5 billion in stock.
The Nasdaq Composite .IXIC dropped 0.19 percent to 6,762.21.
Shares of Twenty-First Century Fox (FOXA.O) slipped 0.30 percent after a report that Walt Disney (DIS.N) was in the lead to acquire much of Fox's media empire, though rival suitor Comcast Corp (CMCSA.O) remained in contention.
The next biggest contributors were shares of Boeing, which rose 1.3% to add about 24.9 points to the Dow; Caterpillar's stock, which tacked on 1.9% to add 18.5 points to the Dow; and Home Depot shares, which rose 1.4% to add about 17.8 points.
Toll Brothers fell 5.74 percent after the company's quarterly profit and revenue missed estimates and it forecast a decrease in full-year 2018 adjusted gross margin.
Declining issues outnumbered advancing ones on the NYSE by a 1.80-to-1 ratio; on Nasdaq, a 1.83-to-1 ratio favored decliners.