Sen. Rand Paul (R-Ky.) is spending the closing leg of the midterm campaign by visibly dialing up the strategy he embraced at its very start: Playing nice with the GOP establishment.

Ahead of a possible run for president, the Kentucky senator is going out of his way to help mainstream Republicans in need of a dose of tea party energy and star power. The moves could help Paul broaden his appeal in the Republican Party in a way his father, Ron Paul, never could.

Paul's latest contribution comes in Kansas, where longtime Sen. Pat Roberts (R) has been trying for weeks to woo Republican voters who fear he he lost touch with them back into his corner. The Kentucky senator plans to campaign Tuesday for Roberts in Kansas, who is locked in a close race with insurgent independent Senate candidate Greg Orman.

A Roberts loss next week could spoil GOP hopes of retaking control of the U.S. Senate -- unless Orman, who hasn't signaled yet which party he would caucus with as a senator, opts to join up with Republicans.

To help Roberts, Paul's super PAC, RAND PAC, plans to air a new television ad today through Election Day that trumpets the Kansas senator's support for a Paul proposal that would have cut off direct U.S. aid or loan forgiveness to Egypt, Libya, Pakistan and any other country where a U.S. diplomatic facility was attacked, trespassed or in any way breached.

Paul's 2012 bill was written in response to the Sept. 11, 2012 terrorist attack on the U.S. diplomatic compound in Benghazi, Libya and was ultimately defeated in the Senate. Similar ad buys with similar TV messages are being made in Kentucky, New Hampshire, Iowa and North Carolina, according to aides.

The Kentucky junior senator rose to stardom as an anti-establishment hero in 2010, winning his primary in an upset against a candidate backed by Senate Minority Leader Mitch McConnell (R-Ky.). His views, particularly on foreign policy and national security, are out of sync with many party leaders. And he sports a following of libertarian-leaning conservatives who often don't fit the mold of the traditional Republican.

But for the 2014 cycle, Paul has been a consummate team player. He endorsed McConnell very early in his fellow senator's primary fight, offering the GOP leader conservative cover against his insurgent challenger. Paul has also cut ads for the Chamber of Commerce, the largest business organization in the country and a group that has often feuded with the tea party. The ads have helped mainstream Republican candidates in North Carolina and Alaska -- two crucial contests in the battle for the Senate majority where Libertarian candidates are also running.

Both McConnell and the Chamber benefited from Paul in 2012. At best, they could be major Paul allies in the presidential bid; at worst, non-hostile entities. They are both tied to deep and powerful donor pools and party kingmakers. So these moves are about much more than direct support -- they're also about opening doors.

Paul's political network has taken a foothold in the establishment at the staff level, too. Jesse Benton, a top ally, worked as McConnell's campaign manager and a top strategist for his leadership PAC. Benton was very well-compensated by McConnell, making more than $500,000 during the last two years -- a sign of his high value in the eyes of the Senate's top Republican.

When Paul's father ran for president, he was never regarded by the GOP establishment as a serious candidate. And he never embraced the mainstream wing of the GOP the way his son has: For example, Ron Paul never endorsed Mitt Romney, even after he was the 2012 presidential nominee.

As the younger Paul mulls whether to run for president, aides note that he's made more than 30 stops over the past two years to help Republican candidates, with several visits to the early presidential primary states of Iowa, New Hampshire and South Carolina. Paul plans to make additional stops to help GOP congressional candidates in Michigan Wednesday, Pennsylvania on Friday and to conclude his election-year travels on Monday in Kentucky, aides said.

Even as Paul has campaigned with the likes of Roberts and Thom Tillis in North Carolina, he has not turned his back on tea party outsiders. Paul recently lent his support to Dave Brat, the insurgent conservative who defeated Eric Cantor in the biggest upset of the primary season.

These campaign stops are a big part of the reason Paul is taken very seriously as a GOP presidential contender. And they reflect his clear understanding of the need to do some back scratching in politics to make some new and important friends. We'll find out over the next two years whether it pays off for him.