Voter ID is an increasingly contentious issue in the 2012 election, and nowhere is that more the case than in Pennsylvania.

A lower court on Tuesday halted implementation of the law for November's election, raising concerns that it might disenfranchise legal voters. If the law is not enforced, whatever chance Mitt Romney had of carrying the state would likely be jeopardized. It could also hurt downballot Republicans.

But how did we get to this point? Here's a quick recap:

March 14, 2012: Pennsylvania Gov. Tom Corbett (R) signs the Voter ID law into effect just hours after it passed on a party-line vote in the newly Republican state legislature. The law would require voters to present specific kinds of photo identification with a valid expiration date. If they cannot provide that, they can cast a provisional ballot and provide a valid ID within six days. The law is one of the most restrictive Voter ID laws on the books, and the strictest in any state that is expected to be competitive in the presidential race. Republicans praise the bill as a measure to prevent voter fraud, while Democrats accuse them of trying to disenfranchise minority, elderly and urban voters, who are more likely to not have the specific photo identification.

April 24, 2012: The law is given a "trial run" in the state's primaries. Voters are asked for photo identification but are not turned away if they can't provide it.

June 25, 2012: Video surfaces of state House Majority Leader Mike Turzai (R) saying, at a gathering of Pennsylvania Republicans the previous weekend, that the law would help them carry the state at the presidential level. "Voter ID, which is going to allow Governor Romney to win the state of Pennsylvania: done," Turzai said while listing his party's accomplishments. This was a problem because the GOP says they are necessary to prevent voter fraud -- not for partisan political gain. Democrats pounce on Turzai's comment as proof of the actual motivation behind the law.

Aug. 15, 2012: A Republican lower-court judge upholds the law, saying opponents have not proven that it infringes on voters' rights and suggesting that estimates of the number of voters who could be turned away are overblown. The law is a "reasonable, non-discriminatory, non-severe burden when viewed in the broader context of the widespread use of photo ID in daily life,” Commonwealth Court Judge Robert Simpson wrote in his opinion, which cites a 2008 U.S. Supreme Court case on an Indiana Voter ID law. Democrats appeal the ruling to the state Supreme Court, but despite Simpson's political leanings, observers suggest his ruling will be hard to overturn.

Sept. 18, 2012: The state Supreme Court sends the case back to Simpson, asking him to determine whether the law can be implemented in time for the November election without disenfranchising any voters. The court suggests that the law might be constitutional, but that not everyone could obtain proper identification in time for this year's election.

Sept. 28, 2012: Romney predicts: "I'm going to win Pennsylvania." But polls continue to show President Obama with close to a double-digit lead, and observers (including The Fix) are generally skeptical -- even with the Voter ID law intact.

Oct. 2, 2012: Simpson orders state elections officials not to enforce the law in November's election, citing concerns that the state would not be able to supply photo ID to all qualified voters who lack it. Simpson effectively extends the "trial run" that was used during the primary, in which officials can ask for identification but can't turn away people who don't provide it. Republicans can still appeal this ruling to the state Supreme Court.