As early as today, the Senate is likely to vote on the first of two competing efforts to temporarily extend tax cuts passed between 2001 and 2010. Neither the Democratic nor Republican measures will pass in the hyper-partisan Senate, but it is instructive to see how the measures stack up. The short summary: The Democrats would increase the deficit by $250 billion, while the GOP would add about $405 billion, compared to what would happen if all of the tax cuts expire on schedule at the end of 2012. Under either plan, nearly all taxpayers would pay less than if the tax cuts are allowed to expire. However, the highest-income households would, on average, pay about $340,000 less under the GOP plan than with the Democrats’ version. But the story is more complicated. In their still-evolving bill, the Democrats left out two changes they have long supported--continuing to protect millions of middle- and upper-middle income families from the Alternative Minimum Tax and preventing the estate tax from returning to its pre-2001 level.  If you include both, the Senate Democrats would cut taxes by $368 billion compared with today's rules. To help sort it out, my colleagues at the Tax Policy Center have put together a nice cheat sheet that summarizes the two bills. In addition, TPC has looked at how the measures would affect households in various income groups and, using Joint Committee on Taxation estimates, how much each plan would cost the Treasury in lost revenue. Both plans extend most of the last decade’s tax cuts for another year (and in some cases two). But there are some big differences. Senate Republicans would allow nearly all of the 2001/2003/2010 tax cuts to continue through at least 2013. As promised, they’d keep low rates on both ordinary and investment income. They would retain an estate tax but only on bequests in excess of $5 million, and at a 35 percent rate. It also appears as if they’d allow a package of low-income tax cuts enacted in 2009, including expansions of the Earned Income Tax Credit and the Child Tax Credit, to expire. As a result, an average household would pay about $2,000 less than if Congress allowed all the tax cuts to expire. Middle income households would pay about $1,100 less.  However, the highest-income 0.1 percent  (those making more than $2.8 million) would be on average $391,000 better off than under current law. For their part, Senate Democrats would extend all the tax cuts for those making $200,000 (couples making $250,000) or less. However, they’d let most tax cuts expire for high-income taxpayers. In the Democrats' plan, the top two rates would revert to 36 and 39.6 percent. Capital gains and dividends would be tax-free for those in the bottom two tax brackets, taxed at 15 percent for those in the 25, 28, and 33 percent brackets, and taxed at 20 percent for those in the top two brackets. The Democrats would extend the AMT patch for 2012 only (the AMT fix technically expired at the beginning of this year). However, TPC also estimated the impact of extending AMT fix for both 2012 and 2013 and extending the 2009 estate tax levels (a $3.5 million exemption and a 45 percent rate). If the Democrats did both, their overall plan would cut taxes by an average of about $1,700, a bit less than the $2,000 break under the GOP plan. Middle-income households would pay about $1,200 less, slightly more than if the Rs had their way. However, the highest-income 0.1 percent  would pay about $54,000 more on average than under current law but almost $340,000 more than they would under the GOP plan. Of course, if you assume that most of todays tax rules are still in place, which the GOP will, the Democrats plan looks like a tax increase for top earners. Low- and middle-income households would pay the same. But about 1.4 percent of taxpayers, all with high incomes, would pay more. Those at the very top would pay about $340,000 more in 2013 than under todays system. If you think of these bills as political markers, the messages are quite clear. And they will give both parties plenty of ammunition for the coming campaign. And that, after all, is the point of the exercise.  This post was updated at 2:25 p.m. on Wednesday, July 25, 2012.