Democrats pushed a $3.5 trillion, 10-year bill strengthening social safety net and climate programs through the House Budget Committee on Saturday, but one Democrat voted “no,” illustrating the challenges party leaders face in winning the near unanimity they’ll need to push the sprawling package through Congress. The Democratic-dominated panel, meeting virtually, approved the measure on a near party-line vote, 20-17. The passage marked a necessary but minor checking of a procedural box for Democrats by edging it a step closer to debate by the full House. Under budget rules, the committee wasn’t allowed to significantly amend the 2,465-page measure, the product of 13 other House committees.