Sen. John McCain (R-Ariz.) will meet with President Obama at the White House Thursday afternoon to plot strategy for passing comprehensive immigration reform. McCain said Obama requested the meeting, which comes at a time political momentum for immigration reform is flagging. McCain and Obama need to shore up the support of wavering allies such as Sen. Marco Rubio (R-Fla.), who has backed off the push to overhaul the nation's immigration laws in a 1,200-page comprehensive bill. Rubio has said the Senate should not try to merge its comprehensive bill with a piecemeal measure coming out of the House. McCain's ally,...