Colleague John Richardson reported Monday night that Republican Charlie Summers is slated to receive another boost in his quest to win a U.S. Senate seat. The assistance, this time in the form of an estimated $500,000 television ad buy from the National Republican Senatorial Committee, marks the third time that Summers has received help from an outside group. 

So far, none of the outside ads designed to help Summers have mentioned him by name, and instead attack independent Angus King or tout Democrat Cynthia Dill (reports suggest that NRSC ads may not alter that trend.). However, the NRSC buy arrives amid the growing sentiment among national Republicans that Maine is one of the GOP’s last remaining hopes to capture the majority in November.

Richardson mentions a recent Politico report in which Republican strategists say they have become more pessimistic about controlling the Senate. The report was followed by a New York Times story that lists Maine among six "tossup" states

Most recent polling shows King with a large lead. However, the NRSC buy is a significant investment. Does the spending mean that national Republicans think Maine is truly winnable, or does it signal a last-ditch effort?

We’ll see, but it’s worth noting that the NRSC is only currently running ads in two other swing states, Montana and North Dakota.

CNN reported Tuesday that Crossroads GPS, the group headed by GOP strategist Karl Rove, was readying a $2.6 million buy in several tight senate races. Maine isn’t included in the buy, but if the NRSC ads can move the needle against King, Rove’s group could very well launch a salvo here. 

After all, a recent report in Bloomberg Businessweek showed that Maine is already on Rove’s radar