Whichever polls you're going on, this election is very close and it's going be decided by a handful of key states. That's why efforts to manipulate the voting process could play a crucial role in the outcome – and why we need vigilance against all forms of voter suppression.

Today we'll be tracking reports of mischief from across the country as this crucial presidential vote unfolds. Keep checking back for updates.

LIVE UPDATES

7.23pm EST, Tuesday 6 November: All day there have been reports of long lines, especially in key battleground states like Ohio. As the polls start to close, remember this (thanks to the Human Rights Campaign for the graphic):

6.18pm EST, Tuesday 6 November: Latinos in the swing state of Colorado are reporting incidents of worrying voter intimidation. Two canvassers were told by sheriff deputies to "call it a day" after being followed and then stopped and checked while going door-to-door encouraging Latinos to vote last week. And a Latina voter reported that a poll worker yelled at her that she should be charged with a felony and serve jail time after she requested help correcting an error on her ballot. While it's unclear how widespread experiences like this have been, these isolated stories are very disturbing.

4.25pm EST, Tuesday 6 November: In Philadelphia, reports indicate that numerous voters are being forced to vote using provisional ballots due to apparent errors in voter rolls – meaning their votes will be counted late, if at all. The difficulty is reportedly causing some voters to leave in frustration, without casting their ballots. In October, an election monitoring group had warned officials that a backlog of 20,000 unprocessed voter registrations was going to cause troubles – and now we're seeing the results.

2.35pm EST, Tuesday 6 November: In Pennsylvania, a voter captured an electronic machine changing his vote for Obama into one for Romney on video – and posted it on YouTube. The machine has now been taken out of service, but it raises the question of how often this type of thing is happening, and what it could mean for the results. Last week, Republicans raised similar concerns that machines were wrongly counting votes for Romney towards Obama. Check out the video below, and if you are voting this afternoon watch carefully!

12.55pm EST, Tuesday 6 November: The Tea Party-affiliated group True the Vote has been barred from observing voting at 30 polling places in predominantly African-American neighbourhoods in Columbus, Ohio. The Columbus Dispatch reports that the group's permission to act as official observers was withdrawn after the candidates who had supported the group's participation withdrew that support amid charges that the applications had been falsified. True the Vote has been accused of being on a mission to suppress Democratic-leaning minority voters across the country. The Dispatch story reports that "one person told the elections board that she attended True the Vote training sessions and the observers were instructed to use cameras to intimidate voters when they enter the polling place, record their names on tablet computers and send them to a central location, and attempt to stop questionably qualified voters before they could get to a voting machine."

11.57am EST, Tuesday 6 November: A Pennsylvania judge has ordered Republican operatives to stop demanding photo ID from voters outside an Allegheny County polling place. The Pittsburgh Tribune-Review reports that the judge ordered the electioneering to stop, saying partisans asking for ID “could have a chilling effect” on voting. Under a new Pennsylvania law, currently on hold, poll workers may ask for ID, but voters are not required to show it. Only official poll workers may legally request ID.

11.17am EST, Tuesday, 6 November: The Tampa Bay Times reports that hundreds and possibly thousands of voters in St Petersburg, Florida, got robocalls from the Pinellas County election supervisor's office telling them polls would be open till 7pm Wednesday. That's wrong, of course. Voting ends at 7pm tonight (Tuesday), and anyone trying to cast a vote after that would be out of luck. Voting officials blame a "glitch" in their robocall system.

10.56am EST, Tuesday, 6 November: The Palm Beach Post in Florida is reporting that voters are arriving at a polling place only to find it's been moved, apparently without notice. (Be sure to read the comments below the blog entries, where readers tell their own stories of voting problems. Some suspect voter suppression, others blame incompetence on the part of election officials.)

10.36am EST, Monday 5 November: Are there reasons to be concerned about somebody monkeying with Ohio voting machines? Brad Friedman at Salon tries to run down a story by freepress.org that reports that mysterious "experimental" software patches are being installed in electronic voting machines in 39 Ohio counties. There's a lot of questions voting officials don't want to answer and a worrisome history of shady software fixes to these black box machines that fuel suspicions. Friedman's conclusion? With little time to investigate before the election, there's no proof of a fire, but there's certainly enough smoke in the "secretive, seemingly extra-legal" actions of election officials to rate a deeper investigation when the election's over.

8.52pm EST, Monday 5 November: Democrats in Florida have settled their lawsuit seeking to force the state to extend polling place hours, in order to address extremely crowded voting conditions in south Florida. Miami-Dade, Broward and Palm Beach counties have agreed to make provisions for voters to get absentee ballots on the spot, alleviating the extremely long lines and waits.

5.45pm EST, Monday 5 November: Tea Party activists with the group True the Vote have been filing challenges to voters' eligibility, supposedly to prevent felons from illegally voting. But Voting Rights Watch has found dozens of legitimate voters in Florida's heavily African-American I-4 corridor who won't find out until they go to vote that their registration has been challenged. Those voters will have to use a provisional ballot and their vote will be counted if election officials determine they are legally registered.

3.15pm EST, Monday 5 November: Massive lines have been reported in Ohio in early voting over the weekend and on Monday, after Republican lawmakers cut back early voting weekends available from five to just one. Adding to the confusion was the decision last Friday afternoon to shift the burden of proof for ID from poll workers to the voter. That technicality could invalidate thousands of legitimate ballots.

2.42pm EST, Saturday 4 November Huge lines and wait times of up to seven hours at early voting locations in south Florida prompted the Florida Democratic party to sue the state to force longer hours to accommodate voters. Earlier this year, Republican governor Rick Scott and the Republican-controlled legislature scaled back early voting hours from 14 to eight days, and cut out the last Sunday before election day. The resulting back-ups in heavily populated Miami-Dade, Broward and Palm Beach counties prompted the lawsuit, asking for an emergency order to expand polling place hours.

Preamble: Recent US history offers serious cause for concern about dirty tricks being deployed to stop people voting. The 2004 race came down to just one state – Ohio – which George W Bush narrowly won, amid accusations that Republican state officials engaged in a variety of tactics to discourage Democrat-leaning voters in urban and African-American districts. And of course, there was the catastrophe of Florida in 2000, where Republican voting officials purged hundreds of thousands of mostly minority voters from the rolls in a so-called "cleanup" of supposed criminals, disenfranchising at least 12,000 legitimate voters. Ultimately, after weeks of legal wrangling and a 5-4 supreme court decision, George W Bush won Florida – and the White House – by just 537 votes.

If you thought those days were over, think again. Laws in 30 states that now require ID and/or limit early voting are expected to disproportionately impact poor, younger and minority voters, groups that typically lean Democrat. Already this year, we're seeing the tactics starting to play out in ways that could swing an election as close as this one.

The good news is that some of the restrictive voter ID laws were invalidated by the courts, at least for this election. But there's no room for complacency.

Sources: Common Dreams, Rolling Stone, Washington Post, Al Jazeera, Salon, CNN, Daily Princetonian, Inquisitr, Columbus Dispatch, Pittsburgh Tribune-Review, Tampa Bay Times, Palm Beach Post, Freepress.org, Truth Out, Huffington Post, New Yorker, Nation, ThinkProgress, MSNBC, The Nation, City Paper, Dispatch Politics