The administration of Gov. Ned Lamont re-launched its campaign for highway tolls in a private two-pronged pitch to wary legislative leaders Wednesday, setting Connecticut’s growing transportation infrastructure needs against a special transportation fund on the verge of insolvency. What he needs is a way to reassure Senate Democrats, who now hold a 22-14 majority after sharing power in an 18-18 Senate for the previous two years, that tolls would not cost the party its majority. House Democrats hold a 91-60 majority, but their leadership has indicated it would not act on tolls until the Senate demonstrates it has the votes.