Just thirty-five Senators in office are strongly pro-choice. But this November, when a third of the Senate seats will be up for grabs, voters have a chance to increase that score.

Exhausted and stultified by the endless Democratic primary? Gagging a little bit every time you hear that John McCain is a "maverick?" With all the attention paid to the presidential slugfest, it’s easy to forget that this November, over a third of the United States Senate will also be up for grabs. While supporters of reproductive rights fervently hope to see the White House back in pro-choice hands, the Senate would act as the crucial check on presidential power should that effort be thwarted. That’s because with veto power over federal judicial appointments, only Senators have the ability to stymie a conservative president’s attempts to place another anti-Roe justice on the Supreme Court.

Today’s Senate Democrats enjoy only a razor-thin 51-49 majority, meaning they can’t prevent conservative filibusters or override a presidential veto. And according to NARAL Pro-Choice America classifications, there are currently just 35 strongly "pro-choice" senators and 17 "mixed choice" senators (including majority leader Harry Reid), but a full 48 "anti-choice" senators. That means when it comes to protecting reproductive health and rights, every open seat can make a difference, whether Republican or Democratic. Here are some of the key races to look out for:

Maine

One might think that two-term Republican Senator Susan Collins would be facing a tougher than usual reelection battle this year because of her constituents’ frustrations with the conservative excesses of the Bush years. Still, polls show Collins leading her Democratic competitor, Rep. Tom Allen, by over 20 points. "Independent Democrat" Sen. Joe Lieberman has said he will campaign for her.

Collins has always enjoyed support from some pro-choice advocates, and has an 83 percent rating from NARAL. She was one of just three Republican senators to oppose the so-called "Partial-Birth Abortion Ban Act" of 2003. Collins has also opposed parental notification laws and the ban on abortions on military bases, which Harry Reid supported. Yet she also voted for a dog-whistle anti-choice bill that would have increased penalties for committing a crime against a pregnant woman, under the rationale that the fetus is a second victim. Collins’ opponent Allen, on the other hand, enjoys a 100 percent pro-choice voting record.

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New Hampshire

At age 43, Republican John Sununu is the youngest member of the Senate. This fall he faces his first reelection battle, but against the same woman he just narrowly defeated in 2002: former Governor Jeanne Shaheen. Sununu has been an ally of President Bush when it comes to restricting abortion access and stem cell research lines, while Shaheen is a pro-choice, Emily’s List candidate. Their race is considered one of the tightest in the nation, and Sen. Chuck Schumer, chair of the Democratic Senate Campaign Committee, has sworn to flood resources into New Hampshire to support Shaheen.

Louisiana

Two-term Democrat Mary Landrieu has a decidedly mixed record on abortion. She supports stem cell research and wouldn’t pull Health and Human Services funding from medical service providers who perform abortion. She also wants to lift the ban on performing abortions on military bases. But Landrieu has voted to ban certain late-term abortion procedures. In her first Senate campaign, she was recommended by Emily’s List, but the group cut her off in 2002.

Landrieu’s opponent is the anti-choice John N. Kennedy, who joined the GOP only last year, after losing a 2004 Senate run as a Democrat. He is currently the state’s treasurer. Landrieu is leading Kennedy by comfortable margins in recent polls, but Louisiana has become more Republican in recent years, so the seat is considered up for grabs.

New Mexico

Thirty-six year Senate veteran Pete Dominici, a Republican, is retiring, and every single one of New Mexico’s Congressional representatives has announced their decision to resign office in order to run for his seat. That’s only three candidates in a small state like New Mexico, but it will still open up a sizable power vacuum. Representing the Democrats is Rep. Tom Udall, who currently represents the northern and eastern parts of the state, including Santa Fe. He has a 100 percent pro-choice voting record.

Republicans Heather Wilson and Steve Pearce will face-off in a June 3 Senate primary. Wilson won reelection to the House in 2006 by just 875 votes, so her central-New Mexico district could be a Democratic pick-up. While she has supported stem cell research and funding for the United Nations Population Fund, she has consistently voted to roll-back girls’ and women’s access to abortion. Pearce is further to her right, with a 0 percent voting record on all reproductive health issues. Due to his anti-choice record, he has won the endorsement of the Susan B. Anthony List Candidate Fund, which usually endorses anti-abortion rights female Republicans. Wilson, though, is not radical enough for the group’s tastes.

Virginia

After serving since 1979, Republican Senator John Warner is retiring this year. Two former governors are competing for the seat; Republican Jim Gilmore and Democrat Mark Warner, the cell phone mogul who transitioned to a career in politics and flirted with a 2008 presidential run. Warner describes himself as a "radical centrist" who respects "responsible choice." As governor, he opposed a 24-hour waiting period for women requesting abortions and said he would fight efforts to chip away at Roe. Polls show him leading Gilmore by a 15 to 20 point margin.

Minnesota

Democratic comedian and professional conservative-basher Al Franken was leading sitting Republican Sen. Norm Coleman in this race — but that was before it was revealed that Franken failed to pay over $50,000 in work-related taxes to 17 states. Franken’s defense is that he overpaid his taxes in Minnesota and New York, his states of residence, during the years in question, but polls show voters aren’t buying it. Coleman is a by-the-book anti-choicer, while Franken is pro-choice and situates his support for abortion rights within his platform for universal health care.

Colorado

Remember Tom Udall, the Democrat running for Senate from New Mexico? His first cousin, Colorado Congressman Mark Udall, is competing to fill the seat of retiring Republican Senator Wayne Allard. Udall’s likely opponent is Republican Congressman Bob Schaffler, who has been implicated in the Jack Abramoff ethics scandal. Scaffler is a committed anti-choicer, while Udall has a 100 percent pro-choice voting record. Polling from April showed Udall and Schaffler locked in a dead heat, so this is one to keep to an eye on.

Alaska

Although currently under investigation for corruption and 85 years old, Republican Sen. Ted Stevens will be seeking another term in November. Stevens calls himself "pro-choice," although he has voted to ban certain abortion procedures and supports parental notification. Stevens opposes comprehensive sex education in favor of abstinence-only. He does, however, support stem cell research and the right of abortion providers to receive grants from the Department of Health and Human Services.

Stevens’ opponent is Anchorage Mayor Mark Begich, the son of a former U.S. Congressman. They are running neck-in-neck.

So there you have it, eight Senate races to watch in ’08, some of them with fascinating implications for pro-choice politics.