Two Senate Republicans said Monday they would support the Obama administration’s financial-overhaul legislation, and Democrats now believe they have the 60 votes needed to push the sweeping bill into law by the end of the week. Sens. Scott Brown of Massachusetts and Olympia Snowe of Maine both said they would vote for the measure when Democrats bring it to a vote, which could happen as soon as this week. Democrats and administration officials believe this gives them the necessary backing to overcome a potential filibuster after weeks of uncertainty and unexpected pitfalls.