One could stretch to make the argument that such a statement is technically true - no Republican has gone on record saying word-for-word "I want to keep large amounts of U.S. troops in Iraq forever." However, top Republican leaders have repeatedly gone on record making statements or taking concrete steps that support actually KEEPING large amounts of U.S. troops in Iraq indefinitely.
Then there is President Bush, who stated just last week that we will not be reducing troops "while I'm the president." That was just the latest statement from the administration and the Pentagon about indefinite troop deployments. For example, in May of 2004, international news service AFP reported that the administration quietly announced that it will "keep high force levels in Iraq indefinitely."
Even if you just look at Tester's opponent, Republican Sen. Conrad Burns (R), it's clear that Republicans are quite brazenly advocating for indefinite deployments of large amounts of U.S. troops in Iraq - regardless of what the public thinks about the war. As the Associated Press reported last week, "Burns said the U.S. must show 'great patience and resolve' and stay in Iraq even if public support for the war continues to erode."
Here's the thing - politicians either support a plan to draw down troops at some point in the future, or they support leaving U.S. troops in Iraq indefinitely. There is no "middle ground" and there is no "third way." Being for one of those positions automatically means you are against the other position, and vice versa - it's a zero sum question, no matter how much the Washington Post, the Beltway neoconservatives or D.C. Republican Party operatives try to fudge the issue with warmed over double talk. In other words, this is the one of the times where Bush's black-or-white world view is actually applicable: you are either for ultimately bringing troops home, or you are against ultimately bringing troops home - and thus for leaving them as targets in the Iraqi shooting gallery indefinitely.
Democratic incumbents and candidates have largely united in support of pushing the White House to begin crafting a plan to get troops out of Iraq. That is a position polls show the majority of Americans support - and a position the stay-in-Iraq-indefinitely Republican Party opposes. While the Post may want to try to create false Democratic rifts in order to fabricate grist for its front page, and may want to push dishonest storylines about the GOP supposedly not being for indefinite troop deployments, the facts speak for themselves.