In politics, as in life, what goes around comes around. Many House Republicans have received a raucous reminder in recent weeks.

Two years after tea party critics invaded town meetings and hectored many Democrats for supporting President Barack Obama’s health-reform plan, opponents of the controversial Ryan budget gave GOP lawmakers — including its architect, Rep. Paul Ryan of Wisconsin — similar treatment.

Critics of his proposals to phase out Medicare and give greater tax breaks to the wealthy, some organized and some spontaneous, invaded GOP town meetings and derided Republican lawmakers for failing to keep campaign promises to concentrate on spurring the economy and creating jobs.

For the Democrats, those unruly 2009 town meetings were the precursor to the party’s losing its House majority in the 2010 mid-term elections. The big question now is whether this spring’s assaults on the GOP will lead to a similar reversal when Americans vote next in 2012.

Already, the experience seems to have complicated Republican plans for some of their proposals. Several top House Republicans indicated they were disinclined to push the follow-up legislation to implement their Medicare changes. But Speaker John Boehner later said he still wants to pass some of them this year.

And the GOP candidates’ defense of the Ryan Medicare plan appears to have given Democrats an opening in a closely watched May 24 special congressional election in a normally Republican district in upstate New York.

On the surface, next year’s political landscape bears some similarities to 2010.

Of 240 House Republicans, 61 represent districts that Obama captured in 2008 and where his presence on the ballot could help Democratic candidates again next year.

One big factor in last year’s Democratic loss of the House was defeat in three-fourths of the 49 districts that elected them in 2008 while simultaneously backing GOP presidential nominee John McCain.

But the GOP has one big ace in the hole as it tries to maintain its biggest House majority since the 1940s. In many key states, including Texas, it controls House reapportionment stemming from the 2010 census.

The authoritative, nonpartisan Cook Political Report says redistricting could help 15 Democratic incumbents and 50 Republicans, including four Texans — Reps. Mike McCaul of Austin, Pete Sessions of Dallas, John Culberson of Houston and John Carter of Round Rock.

More than half of the 50 Republicans on this list are freshmen, and 16 represent districts where Obama either won or received at least 49 percent.

The reason so many Republicans could benefit from redistricting is GOP success in last year’s battles for state legislatures and governorships.

It gave the party control of the governorship and legislatures in 21 states, including Texas, compared with just 11 for the Democrats. The other 18 have divided control.

Republicans control redistricting in Indiana, Michigan, North Carolina, Ohio, Pennsylvania and Texas, where last November’s GOP House successes left little opportunity to gain more seats but where Republicans could lock in their gains through redistricting.

In Texas, this would presumably mean protecting freshmen Reps. Blake Farenthold of Corpus Christi and Francisco Canseco of San Antonio, whose districts are heavily Hispanic.

Without redistricting, Republicans could be in danger of losing the 25 House seats Democrats need to regain the majority they lost in 2010.

That’s because Obama likely will run strongly in most of the 61 districts that voted for him in 2008 and a Republican House member in 2010. Eight are in Illinois, Obama’s home state and one of the few big states where Democrats still control the redistricting process. Ten others are in California and Florida, where new rules could limit partisan redistricting.

And 18 are in other industrial states that Obama carried but where the GOP controls the process in 2011.

The last time the House majority changed hands for a third time in four elections was in 1894. But Republican vulnerability on Medicare makes it at least a possibility in 2012, ironically a year in which the GOP has a good chance of regaining the Senate.