It may have been Thursday, but it was hump day in the House for the landmark climate change bill.With critical backing from the White House, Democratic leaders leaned into their push to round up support for the package ahead of a scheduled Friday vote. They broadcast cautious confidence while acknowledging work remains to win over some holdouts, many of them moderates.“We’re in striking distance,— said one senior Democratic aide.The White House fully engaged in the whipping effort Thursday, which kicked off in the morning when White House senior adviser David Axelrod pitched the measure to the Democratic Caucus. President Barack Obama, White House Chief of Staff Rahm Emanuel and other senior administration officials worked the phones throughout the day. And the sales job was expected to carry into the evening, when Obama hosted lawmakers at the White House for a luau-themed Congressional picnic.Speaker Nancy Pelosi (D-Calif.), who has staked addressing climate change as a legacy project, had scheduled former Vice President Al Gore to make the case to her caucus Thursday afternoon. But Pelosi canceled the visit, explaining it was no longer necessary. Republican leaders sent an e-mail suggesting that Gore was “Too Toxic for Dem Leaders Targeting Heartland Democrats.— But Pelosi explained the decision as a “question of what was energy efficient for the vice president.— Gore remained in Nashville, Tenn., to work the phones.“It’s down to the nits and nats at this point, and whether people have been able to digest it all,— said Rep. Dennis Cardoza (D-Calif.), a prominent moderate who is backing the bill.Throughout the day, Pelosi and her deputies could be seen stalking the aisles of the House chamber during votes, buttonholing their slowly shrinking list of targets.But several Democratic moderates said they continue to harbor reservations about the bill. Their concerns ranged from the general — as lawmakers struggled to get familiar with a complex and sprawling measure that clocked in at 1,201 pages — to the parochial.Rep. Bill Pascrell (D-N.J.) said he is leaning against the bill, pending the addition of a provision to support projects to convert waste products into energy, a home-state industry. Rep. John Boccieri (D-Ohio), one of many to field a call from Obama, said he is pushing for the authorization of a Midwestern power marketing authority. Rep. Henry Cuellar (D-Texas) was facing intense pressure from leaders and the White House, including a call from Labor Secretary Hilda Solis, a friend from her tenure in the House and a neighbor at his condo complex. Cuellar has described himself as “leaning no,— since farm groups back home remain opposed. But the Texas Democrat said a call from Obama was having an impact on his thinking. “He’s pretty persuasive,— he said of the president.Democratic leaders are hoping to pick up five to 10 moderate Republicans, and they also trained their fire on those lawmakers on Thursday.At one point, Pelosi chased after Rep. Timothy Johnson (R-Ill.) as he passed by in the hall to gauge his support on the bill.“Well, we’re still thinking about it,— Johnson said.Pelosi, holding Johnson’s arm and smiling, replied, “Still thinking. If you have any questions, give me a call.—Jennifer Bendery contributed to this report.