Sen. Lamar Alexander won Tennessee's Republican primary Thursday, effectively ensuring he will get a third term in office and a chance to set the Senate's agenda on labor issues if the GOP wins control of the chamber this fall.

Alexander has a shot at becoming chairman of the Senate Health, Education, Labor and Pensions Committee, as polls show Republicans have a better than even chance of taking back the Senate in November. That is likely to be a big frustration for Big Labor, since Alexander has consistently voted against its agenda.

The 74-year-old Alexander is an old-school lawmaker noted for his collegiality. He's a conservative but a relatively moderate one, and he has shown a willingness to work with the other side and even cut deals on issues.

That sparked a Tea Party primary challenge against Alexander. It ultimately failed but held him to about 50 percent of the vote. He ran unopposed in 2008.

Alexander's record on labor issues is conservative, but with caveats. He has a lifetime rating of 18 percent from the AFL-CIO. He has voted against most of President Obama's Democratic nominees to the National Labor Relations Board and opposed confirming Labor Secretary Tom Perez.

Alexander has also opposed expanding the Davis-Bacon wage law, which gives unions a leg up in federal contracting, and opposed the Employee Free Choice Act, which would have largely replaced federally monitored union organizing elections with so-called "Card Check" elections. He also voted to strip the NLRB of its power to impose speedy union elections on businesses.

He is the lead Senate sponsor of the Employee Rights Act, which would require federally monitored elections before any union is recognized and make it easier for unionized workers to object to their dues being used for political purposes. Late last month, he called for repealing Davis-Bacon.

Alexander is not somebody unions would like to see steering the committee that has jurisdiction over them. Yet his AFL-CIO rating does indicate that he votes with Big Labor about one out of every five times. Some of those votes are notable.

In late 2008, Alexander voted against an amendment sponsored by then-Sen. Jim DeMint that would have prohibited the auto industry bailout. The following year, he opposed a DeMint amendment to the Lilly Ledbetter Fair Pay Act that would have created a national right-to-work law. Alexander objected to that amendment even though he subsequently voted against the bill. He also voted in favor of Obama's first labor secretary, Hilda Solis.

On other issues, Alexander has common ground with Big Labor: He backed the "Gang of Eight" immigration reform bill in 2013, which Big Labor helped to negotiate. He's also a longtime advocate of a national Internet sales tax. Big Labor favors a tax because it would mean more revenue for states and localities and therefore more money for public sector unions.

Even when Alexander has opposed unions, his opposition hasn't necessarily been an obstacle for them. For example, while he voted against Obama's NLRB nominees Kent Hirozawa and Nancy Schiffer, he also agreed to allow full Senate votes on them, ensuring they would be approved. That, in turn, assured that Democrats would control the NLRB with a 3-2 majority, which was what Big Labor really wanted all along.

"I will not vote to report these two nominees favorably out of committee, but I will not support any effort to delay their consideration on the floor," Alexander said at the time. "The nominees will have an up or down vote."

This was part of a deal the GOP struck that summer with Senate Majority Leader Harry Reid, D-Nev., to preserve the Senate filibuster. It wasn't a very good deal, though. By the end of the year, Reid went ahead and abolished the filibuster for most presidential nominees anyway.

So officially, Big Labor will denounce Alexander should he become the next chairman of the Health, Education, Labor and Pensions Committee. Privately, union bosses will probably be telling themselves it could be a lot worse.

Conservatives should say the same thing. While the current committee chairman, Sen. Tom Harkin, D-Iowa, a staunch union ally, is retiring, the Democrat next in line behind him is Maryland's Barbara Mikulski, also a major labor supporter.