But is it on par with the biggest gerrymander in recent history?

Redistricting experts are already comparing the map to the one passed by Texas Republicans in 2003 under the guidance of then-U.S. House Majority Leader Tom DeLay (R-Texas). The Texas map eventually led to the exit of seven Texas Democrats, while the Illinois map draws 10 of the state’s 11 congressional Republicans into districts with other incumbents and could knock out six of them.

The Illinois map is expected to pass today, and Democratic governor Pat Quinn (D) is expected to sign it if it comes to his desk.

“In the pantheon of gerrymanders, this one appears to have similarities to the Texas re-redistricting of 2003,” said George Mason University political science professor Michael McDonald.

David Wasserman of the Cook Political Report said the Texas map and Illinois map “compare pretty well.”

But is it really an apples-to-apples comparison?

McDonald and Wasserman both added caveats.

Wasserman noted that the Texas map was more divisive because it played with majority-minority districts and was done outside the normal window for redistricting — a.k.a. “mid-decade.”

The latter fact, in particular, is key, because the timing of the Texas gambit made it an even more transparent political power grab.

McDonald also noted that the Texas map in 2003 went after much more entrenched incumbents than the Illinois map, which largely targets GOP freshmen who already had a tough 2012 ahead of them no matter the lines.

“Every redistricting is different, and there is no true comparison of potential seat gains between these two maps,” McDonald said.

At the same time, the practical effect of the maps is undeniably similar.

The 2003 Texas map immediately ended the careers of six of the state’s 17 congressional Democrats — all six lost reelection in 2004 — and a seventh later in the decade.

The Illinois map, meanwhile, could wipe out as many as six of the state’s 11 Republicans, though it’s not clear how many of those victories will come immediately or at all.

Given that Illinois has 13 fewer congressional districts than Texas, the percentage of seats that could swing is actually bigger than in Texas, even if the raw number is likely to be smaller.

Perhaps the most shocking aspect of the Illinois map is how it puts 10 of the state’s 11 congressional Republicans into districts with other incumbents. Not content to simply make their home districts more difficult, Democrats are forcing those incumbents to either run against fellow incumbents or run in districts where they don’t live.

The Texas map at least left a few Democrats alone albeit because there really wasn’t much of a choice in some urban areas, where majority-minority districts must be protected by law.

Above all, though, a gerrymander is in the eye of the beholder. And when it comes to aesthetics, the lines of the Illinois proposal aren’t especially egregiously drawn — at least not to the naked eye. Experts also note that it may be more compact than the current map, which features some pretty oddly shaped districts itself.

One key element, though, is that many of the suburban Chicago districts are contorted in odd ways, much like they were in the Texas suburban seats after the 2003 line-drawing.

By stretching eight districts in odd directions out from Chicago, Democrats give each seat a significant amounts of Democratic voters and draw Republican incumbents into other districts. The results are significant:

* Rep. Judy Biggert’s (R) district was eliminated altogether, leaving her to run against a fellow incumbent if she doesn’t want to retire — potentially Rep. Peter Roskam (R).

* Rep. Joe Walsh (R) has been drawn into the same district as fellow freshman Rep. Randy Hultgren (R), leaving Walsh’s old 8th district significantly more Democratic. Walsh could run in either district.

* Reps. Bob Dold (R) and Adam Kinzinger (R) now live in liberal Chicago-based districts. Dold will likely run again in the tough 10th district — where he no longer lives — while Kinzinger will likely run elsewhere as well, potentially against Rep. Don Manzullo (R).

* Further downstate, Rep. Bobby Schilling’s (R) western 17th district would become a more Democratic northwestern district that he would have trouble holding. Rep. Aaron Schock (R) was also drawn into the district, but he will likely run in the much safer 18th district in the western-central part of the state.

* And Rep. Tim Johnson’s (R) eastern 15th district is now a southeastern swing district that he could have difficulty holding (it went 55 percent for President Obama in 2008, per Wasserman’s calculations).

That’s six Republicans — Biggert, Walsh, Dold, Kinzinger, Schilling and Johnson — who could very well be replaced by Democrats in the 113th Congress.

The map isn’t final, but it’s close, with the deadline being today for the state Senate to pass it. (The state House passed it Monday).

There is little reason to pretend that it isn’t a significantly political map, and Illinois’s reputation as a bare-knuckled political state will only be furthered by the lines the state legislature has produced.

But it’s important to look at the map in context too.

The reason that so many seats are at stake is because the GOP’s majority in the delegation was so disproportionate. Democrats are simply trying to gain whatever seats they can — just like Republicans will do in other states. The problem for the GOP is that it’s much tougher for them to add winnable districts because they already control so many competitive ones.

Basically, this was Democrats’ one opportunity nationwide to add winnable districts during a cycle in which Republicans will be looking to make smaller gains spread out over many more states. The Illinois plan has plenty of shock value, but much of that is because of the opportunity that presented itself — an opportunity that Republicans, put in the same position, may very well have taken too.

The question now is how much this emboldens legislators in other states to stretch their maps for their parties’ political gain. If a tone is set, it’s going to be harder for other politicans to resist.