Republican leaders are finally climbing on board President Donald Trump’s plan for a wall on the U.S.-Mexico border — and they say they’re ready to spend as much as $15 billion to build it. House Speaker Paul Ryan and Senate Majority Leader Mitch McConnell both suggested Thursday that, after months of studiously ignoring the border wall proposal, they’re now ready to act on the wall as part of a spending request they expect from Trump that would help jump-start construction.