TOPSHAM — The Republican Party’s chances of retaking control of the U.S. Senate in 2012 may hinge in part on an act of kindness more than four decades ago.

Paul LePage ran away from home at age 11 to escape an abusive father. Several years later, he was befriended by Peter Snowe, a businessman and budding politician. Snowe helped in the 1960s to put the homeless teenager on a course that led in 2010 to the Maine governor’s mansion.

Within weeks of LePage’s victory, he returned the favor, endorsing the re-election of Republican Sen. Olympia Snowe, Peter Snowe’s widow, shielding her from a serious challenge from tea party activists who had helped make LePage governor.

In an interview, Snowe called LePage’s support “extremely helpful” in easing relationships with tea party activists. “He has a measure of credibility with them, and that’s been critically important,” she said.

Tea party activists have eyed 2012 as a chance to defeat Snowe, 64, who voted with Democrats on the bank bailout, President Obama’s economic stimulus and other issues. She was the only Senate Finance Committee Republican to back the health-care overhaul, although she opposed the final bill.

Snowe’s re-election could help decide whether Republicans take Senate control. Democrats hold 53 of 100 seats, and Snowe is favored by analysts to prevail in a general election.

Still, the third-term senator has to be “on guard,” said Stu Rothenberg, editor of the nonpartisan Rothenberg Political Report in Washington.

The 2010 elections held surprises, most notably when tea party favorite and political novice Christine O’Donnell defeated nine-term Rep. Mike Castle in Delaware’s Republican Senate primary. O’Donnell later lost the general election to Democrat Christopher Coons.

The LePage endorsement is “huge” and a key reason Snowe hasn’t drawn a more competitive challenger in nominating caucuses three months away, said Jennifer Duffy, editor of the Washington-based nonpartisan Cook Political Report. Snowe faces Scott D’Amboise, a former Lisbon Falls town selectman, and Andrew Ian Dodge, a former Tea Party Patriots Maine coordinator.

The governor’s motivation wasn’t political; it was personal. LePage believes his help from Peter Snowe, who died in a 1973 car accident, was a turning point, said Brent Littlefield, LePage’s senior political adviser.

When the two met, LePage was a teenager shuttling between homes of two families. A native French speaker, he struggled with a college entrance exam and Peter Snowe persuaded Bangor- based Husson University to let him take it in French. LePage, who declined an interview, was admitted and, after graduating, became successful in business.

“Gov. LePage has made it clear that he has had a close personal connection to Olympia Snowe as a result of the role her first husband, Peter Snowe, played in his life,” Littlefield said. “That relationship transcends politics.”

Pete Harring, a tea party activist who operates the website teapartymaine.org, is among those who say the senator appears safe. “I don’t see any viable candidates out there capable of taking on Olympia,” he said.

National conservative groups including FreedomWorks, Tea Party Express and Club for Growth are currently focused on Republicans elsewhere.

“In a world of scarcity, we can’t do everything,” said Brendan Steinhauser, political director of FreedomWorks. His group is targeting Sen. Dick Lugar of Indiana and Sen. Orrin Hatch of Utah in their Republican primaries.

Snowe raised $3.5 million in campaign funds as of Sept. 30, with $3.2 million in the bank. D’Amboise raised $364,534 and had $182,021 on hand, while Dodge didn’t reach the $5,000 threshold for disclosure, financial disclosure reports show.

Snowe, who was remarried to then-Gov. John McKernan, also is adapting to the political environment. She has held meetings with tea party activists, and is stressing measures such as her bill to reduce use of deficit-raising budget “gimmicks.”

A supporter of Obama’s two Supreme Court nominees, Sonia Sotomayor and Elena Kagan, this year Snowe voted to block some of his appellate court picks. She voted in April for a proposal by Senate Republican Leader Mitch McConnell of Kentucky, barring the Environmental Protection Agency from regulating greenhouse-gas emissions.

Snowe said her votes are consistent with past views and dismissed as “political chatter” claims that she’s leaning to the right.

Maine’s economy ranked 43rd among states in the year ending June 30, according to the Bloomberg Economic Evaluation of States Index, which uses data on employment, real estate, taxes and local stocks. The state’s employment grew by 0.6 percent over the year, according to the study.

After touring a small-business expo in Topsham, where she chatted with business owners about her efforts to cut red tape and expand health coverage, Snowe said she’s taking nothing for granted.

“There’s a very different dynamic under way in these elections whereby you have national organizations that can weigh in with millions of dollars in weeks prior to an election,” Snowe said. “I can’t afford to underestimate in any capacity, in any way.”