In what would be a 3-2 vote split along political party lines, the Federal Communications Commission has finally gotten close to approving the merger between Sirius (SIRI) and rival XM (XMSR).

The swing vote on the deal is Commissioner Deborah Tate, a Republican appointee. Both Reuters and The Wall Street Journal say she is close to filing her vote in favor of the deal.

The two Democrats on the five member commission – Jonathan Adelstein and Michael Copps – have voted no on the combination. Copps Monday gave an unconditional no vote on the deal, and earlier today, Adelstein voted no after he made no progress getting the companies to agree to conditions like a six-year service price freeze and mandatory public access to a quarter of the combined companies’ airwaves.

The FCC approval will include a $19 million settlement related to enforcement issues. The fine involves an FCC inquiry into radio violations. XM was forced to pull some radios off the market because the signal transmission crossed over into the airwaves of conventional radio channels.

Sirius and XM filed for a merger review with regulators in February 2007.  Just over a year later, the Justice Department approved the deal, saying that conventional radio and MP3 players like Apple’s (AAPL) iPods were sufficient competition to keep Sirius from setting high prices.

The FCC was a more difficult hurdle, in part because the agency wrote the original satellite radio charter, which specified that the two radio wave licenses should be in separate hands to foster competition.

In an effort to ease the concerns that the satellite duo would use its monopoly status to gouge consumers, the companies proposed new price plans like 50-channel and 100-channel a la carteofferings that would cost $13 and $15 a month, prices that would stay static for three years. XM and Sirius currently charge $12.95 a month.

The companies also promised to set aside 4%, or 12 channels, for outside access like public service and minority programming.

But as the merger approval process dragged on for nearly a year and a half, the two companies saw growth cool and losses mount. And as new car sales fell, the satellite radio sector suffered as well. Investors worried about the perpetual need for new financing and the prospects of recapitalization pushed the stocks down. XM shares are down 23% from the pre-merger announcement level and Sirius has dropped 37% in the same period.

Looking ahead, if the companies manage to bring their operations together and find new sources of cash, the new entity will likely take aim at lowering high-priced programming deals like the five-year $500 million contract with Howard Stern, which expires in 2010.