These days, you hear it everywhere — from Republican donors and veteran operatives, and at Capitol Hill watering holes. A few weeks ago, it was a wishful rumor floating in the Beltway ether. Now, sources close to the Romney campaign say it’s for real, that the taciturn former Massachusetts governor is quietly warming to the idea…

Yet behind the scenes, Ryan’s stock has been steadily rising. Romney, a former Bain Capital consultant who relishes data and metrics, has clicked with the youthful Badger State wonk. They have campaigned together and speak frequently on the phone, comparing notes on policy and strategy. And earlier this year, with Ryan’s blessing, Romney hired three of Ryan’s Budget Committee advisers to help him in Boston…

In late June, National Review Online reported that the Romney campaign was seriously vetting Ryan — and that Ryan had shared paperwork detailing his financial and personal records with a handful of Romney’s Boston-based counselors.

Since then, sources say, Ryan has slowly floated to the top of Romney’s vice-presidential shortlist. In conversations with senior advisers and donors — at the campaign’s summer retreat in Park City, Utah, and at his lakefront home in New Hampshire — Romney has repeatedly expressed his admiration for the Wisconsin lawmaker.